Physical time travel

There is good evidence that human time travel has occurred. To explain, let’s first define the term. We mean physical time travel, not travel by wishing or dreaming or sitting still and letting time march on. In any case of physical time travel the traveler’s journey as judged by a correct clock attached to the traveler takes a different amount of time than the journey does as judged by a correct clock of someone who does not take the journey.

The physical possibility of human travel to the future is well accepted, but travel to the past is more controversial, and time travel that changes either the future or the past is generally considered to be impossible.

Our understanding of time travel comes mostly from the implications of Einstein’s general theory of relativity. This theory has never failed any of its many experimental tests, so we trust its implications for human time travel.

Einstein’s theory permits two kinds of future time travel—either by moving at high speed or by taking advantage of the presence of an intense gravitational field. Actually any motion produces time travel (relative to the clocks of those who do not travel), but if you move at extremely high speed, the time travel is more noticeable; you can travel into the future to the year 2,300 on Earth (as measured by clocks fixed to the Earth) while your personal clock measures that merely, let’s say, ten years have elapsed. You can participate in that future, not just view it; you can meet your twin sister’s descendants. But you cannot get back to the twenty-first century on Earth by reversing your velocity. If you get back, it will be via some other way.

It's not that you suddenly jump into the Earth's future of the year 2,300. Instead you have continually been traveling forward in both your personal time and the Earth’s external time, and you could have been continuously observed from Earth’s telescopes during your voyage.

How about travel to the past, the more interesting kind of time travel? This is not allowed by either Newton's physics or Einstein's special relativity, but is allowed by general relativity. In 1949, Kurt Gödel surprised Albert Einstein by discovering that in some unusual worlds that obey the equations of general relativity—but not in our world—you can continually travel forward in your personal time but eventually arrive into your own past.

Unfortunately, even if you can travel to the past in the actual world you cannot do anything that has not already been done, or else there would be a contradiction. In fact, if you do go back, you would already have been back there. For this reason, if you go back in time and try to kill your childhood self, you will fail no matter how hard you try.

While attempting this assassination, you will be in two different bodies at the same time.

Here are some philosophical arguments against past-directed time travel. I suggest that none of these are convincing. The last one is subtle.

1. If past time travel were possible, then you could be in two different bodies at the same time, which is ridiculous. 

2. If you were presently to go back in time, then your present events would cause past events, which violates our concept of causality. 

3. Time travel is impossible because, if it were possible, we should have seen many time travelers by now, but nobody has encountered any time travelers. 

4. If there were time travel, then when time travelers go back and attempt to change history they must always botch their attempts to change anything, and it will appear to anyone watching them at the time as if Nature is conspiring against them. Since observers have never witnessed this apparent conspiracy of Nature, there is no time travel. 

5. Travel to the past is impossible because it allows the gaining of information for free. Here is a possible scenario. Buy a copy of Darwin's book The Origin of Species, which was published in 1859. In the 21st century, enter a time machine with it, go back to 1855 and give the book to Darwin himself. He could have used your copy in order to write his manuscript which he sent off to the publisher. If so, who first came up with the knowledge about evolution? Neither you nor Darwin. Because this scenario contradicts what we know about where knowledge comes from, past-directed time travel isn't really possible. 

6. The philosopher John Earman describes a rocket ship that carries a time machine capable of firing a probe (perhaps a smaller rocket) into its recent past. The ship is programmed to fire the probe at a certain time unless a safety switch is on at that time. Suppose the safety switch is programmed to be turned on if and only if the “return” or “impending arrival” of the probe is detected by a sensing device on the ship. Does the probe get launched? It seems to be launched if and only if it is not launched. However, the argument of Earman’s Paradox depends on the assumptions that the rocket ship does work as intended—that people are able to build the computer program, the probe, the safety switch, and an effective sensing device. Earman himself says all these premises are acceptable and so the only weak point in the reasoning to the paradoxical conclusion is the assumption that travel to the past is physically possible.

I recommend an alternative solution to Earman’s Paradox. Nature conspires to prevent the design of the rocket ship just as it conspires to prevent anyone from building a gun that shoots if and only if it does not shoot. I cannot say what part of the gun is the obstacle, and I cannot say what part of Earman’s rocket ship is the obstacle.

Brad Dowden

Department of Philosophy

Sacramento State

How I learned to stop worrying and love moral relativism

This is partly autobiographical. I used to spend a lot of time thinking about metaethical issues and arguing for a kind of moral realism that would be incompatible with moral relativism, but I no longer worry so much about those kinds of issues. You probably don’t care about Swan intellectual autobiography, but I’ll outline an argument that gave me a push.

I’ll start with a definition. Many associate moral relativism with the view that no moral directives are justified or true. They then worry that moral relativists must think that any moral directive is as good or plausible as any other and so anything goes. But this is mistaken. Moral relativists think moral directives can be justified, but the justification of moral directives is relative to the beliefs, values or commitments of a group of people. This means that moral directives aren’t objective in the sense of applying regardless of people’s beliefs, values or commitments. Their justification, and the legitimacy of holding people to them, depends on their beliefs, values and commitments.

Here’s the argument:

1. M is a distinctively moral directive only if it provides reasons for acting.

2. R is a genuine reason for action for an agent only if it is capable of motivating that agent.

3. Therefore, M is a moral directive only if it is capable of motivating an agent.

Premise 1 is a statement of internalism about morality and reasons. It is a conceptual claim about the semantics of moral directives: claims of morality are essentially normative in the sense that there’s a necessary connection between them and practical reason. Moral claims employ terms that are evaluative, action-guiding and prescriptive. Of course, many non-moral claims, like judgments of etiquette, aesthetics, and prudence, have this semantic feature, as well. Some philosophers have exploited this fact in an attempt undermine morality/reasons internalism. But morality is supposed to be distinctive from etiquette, aesthetics, and prudence in the categoricity or authoritativeness of the claim. Something that’s a genuine M has ‘practical clout’ or ‘oomph’, such that someone who said ‘I know it’s M, but I don’t really care about M’ is making some kind of mistake. A moral directive adverts to reasons or considerations that cannot be legitimately shrugged off in this facile way.

This view about the connection between the requirements of practical reason and the requirements of morality is a species of moral rationalism. Moral rationalists usually say that the requirements of morality are practically decisive, but I only say that claims of morality purport to provide reasons for action that have greater deliberative significance or oomph than other practical directives. This version of the thesis avoids, on the one hand, the suggestion that morality has absolute weight in practical deliberations, and, on the other hand, the implication that morality is merely a system of hypothetical imperatives.

Premise 2 is a statement of existence internalism about the connection between reasons and motives. It is very often associated with Neo-Humean theories of motivation. Some consideration provides an agent with a genuine normative reason for action only if it is capable of playing a motivational role in her deliberations. This is just what it means for some consideration to be a reason for the agent. This statement of internalism, then, is a thesis about what has to be true in order for a reason statement truly to apply to an agent. It must connect up with things the agent cares about, or which are deliberatively accessible. This means that externalists about reasons and motivation are wrong to think that an agent has a reason for action when the proffered considerations are deliberatively inaccessible. An agent cannot sensibly be said to possess a reason that is deliberatively inaccessible to her, and so it cannot be a reason for her. The externalist could say, “Tuff. We’ll still apply the reason statement to her,” even if the proffered considerations are deliberatively inaccessible from her point of view. But that makes it sound less like the kind of thing that we should see as an authoritative directive and more like the kind of thing that would be an authoritarian directive.

The conclusion in 3 is a thesis about how to identify the contours of genuine moral directives. Understood this way, premise 2 is presenting answers to the questions raised by premise 1. Moral directives essentially claim that some agent has a significantly weighty reason to act (or avoid acting) in some way. They purport to direct others authoritatively. What, if anything, could possibly justify these claims? Premise 2 suggests the response that moral claims directed to an agent are appropriately justified in terms of considerations that are reasons for her. It follows, then, that moral directives have authoritative normativity when (and because) they are grounded in her rational and evaluative commitments; the authority that grounds these claims is her own.

In other words, the connection between normative reasons and motivation (in 2), and so the connection between morality and motivation (in 3), is read in such a way that an appropriate connection to motivation is what makes it the case that R is a genuine reason for action and M is a genuine moral directive. This is moral relativism. The most obvious objection is that moral relativism just gets the contours of morality badly wrong. Doing the moral thing cannot be so easy – like shooting an arrow, drawing a circle around where it lands and calling it a ‘bulls-eye.'

As I said, I’m not so worried anymore about this implication, but I can say more in the comments. What’s attractive to me about relativism is that it secures the distinctive authoritative status of moral judgments without authoritarian bossing around.

Kyle Swan

Department of Philosophy

Sacramento State

Suicide and love: Do actions speak louder than words?

The spark for this post came from an offhand sentence in a recent student paper—and the paper wasn’t even on suicide:

“To Brittany Maynard, the cost of treatment afflicting her with a bald head, 1st degree burns, morphine-resistant pain and suffer from cognitive abilities outweighed the benefit of spending the last six months with the people she loved in the condition she is currently in."

If you do not yet know about Brittany Maynard’s publicly pre-announced suicide—her now-famous editorial “My Right to Die with Dignity at 29” came out only last month—she moved from California to Oregon for one reason and one reason only: to legally obtain a prescription of lethal drugs from an Oregon doctor.

When I Googled Brittany’s name today (November 21), the first listed link was a piece on Cosmopolitan.com (!) promoting a posthumous Compassion & Choices video released yesterday (November 20) which uses Brittany’s tragic circumstances to again promote its own political goals.

There are many things worth discussing about Brittany’s tragic situation and decision, the political goals of C & C, and the relations between them. But in this short post I’d like to make just one small point that relates to something unsettling I’ve noticed about what Brittany constantly stressed in her editorial and her videos: the love between her and family and friends.

I’m reluctant to even attempt making this point. But here goes:

My decision to take my own life for prudential reasons—reasons referring to the anticipated benefits and burdens of continuing to live—necessarily makes a certain kind of statement—not merely about the value of my life to me, but the value of others’ lives to me.

(This point is different than the oft-heard claim that my decision to take my life because of a condition I have—like a brain disease—necessarily expresses a certain kind of statement about the value of other people’s lives with that condition.)

One can make this point strongly, and in ways that sound harsh. But one can make it in softer ways as well.

Here’s a strong statement of the point by G. K. Chesterton over a century ago (1902):

“Grave moderns told us that we must not even say “poor fellow,” of a man who had blown his brains out, since he was an enviable person, and had only blown them out because of their exceptional excellence. Mr. William Archer even suggested that in the golden age there would be penny-in-the-slot machines, by which a man could kill himself for a penny. In all this I found myself utterly hostile to many who called themselves liberal and humane. Not only is suicide a sin, it is the sin. It is the ultimate and absolute evil, the refusal to take an interest in existence; the refusal to take the oath of loyalty to life. The man who kills a man, kills a man. The man who kills himself, kills all men; as far as he is concerned he wipes out the world. His act is worse (symbolically considered) than any rape or dynamite outrage. For it destroys all buildings: it insults all women. The thief is satisfied with diamonds; but the suicide is not: that is his crime. He cannot be bribed, even by the blazing stones of the Celestial City. The thief compliments the things he steals, if not the owner of them. But the suicide insults everything on earth by not stealing it. He defiles every flower by refusing to live for its sake. There is not a tiny creature in the cosmos at whom his death is not a sneer. When a man hangs himself on a tree, the leaves might fall off in anger and the birds fly away in fury: for each has received a personal affront. Of course there may be pathetic emotional excuses for the act. There often are for rape, and there almost always are for dynamite. But if it comes to clear ideas and the intelligent meaning of things, then there is much more rational and philosophic truth in the burial at the cross-roads and the stake driven through the body, than in Mr. Archer's suicidal automatic machines…”

Here’s a softer, narrower, more cautious statement of the point (from me):

Whether or not you think it morally wrong or a sin, my choice to end my life for prudential reasons is not only a commentary on the value I place on my life, but is also a commentary on the value I place on the potential and actual contents of my life—including the people I love.

Of course, not all suicides are equal in this way, or even made for prudential reasons in the first place: Socrates is not Saul, Romeo is not Robin Williams, and Juliet is not Judas.

But so-called ‘rational’ suicides—in particular, those in which a mentally competent adult decides to take her own life because she fears the anticipated blessings of continuing to live will be outweighed by the anticipated burdens—cannot but send a jarring message to loved ones.

The message? “My life is no longer worth living.” Translated? “You are no longer worth me living for.”

When I choose to end my life on purpose for prudential reasons, even though my words to those surrounding me may be “I love you,” my actions are, at the same time, saying, “I would rather die than spend more time with you.”

I think this interpretation of my act is correct even factoring in my fear of pain and losing control.

Brittany Maynard and those like her are sometimes treated primarily as victims—of disease, or C & C, or both. It’s human nature to pity victims and to try to comfort them, reassure them, give them what they want, and avoid causing them to feel guilt or shame.

But perhaps treating them this way risks morally infantilizing them.

Why not treat them like moral adults, and show them how their actions speak like words?

Getting along with moral disagreement

Thanksgiving is around the corner for Americans. It’s a time for food, family, and thanks, but also arguments about politics. This used to be tolerable to some, but now the country feels so polarized that many find it too exhausting to engage in discussion with those who have different views.

This is just one way in which the unhealthy divide in this country manifests itself. Even if there is a sense in which we have always been so divided, it’s toxic. And one side is not more to blame than the other. Liberals think conservatives are certifiably insane and vice versa. Neither camp seems willing to locate or concede any common ground. The government shutdown we dealt with this time last year is one consequence, thanks to our pathetic “do nothing” congress. Obama and McConnell have recently vowed to get along better, but we can only hope these aren’t empty promises from Washington.

Regardless of how the new congress behaves, we should do better. Often we cast our moral and political opponents as evil and unreasonable, rarely making a serious effort to understand why anyone would think differently. As psychologist Jonathan Haidt says, most everyone is motivated to do what they think is right. Liberals, for example, err when they “understand conservatives as motivated only by greed and racism.”

View on TED

Haidt’s own research suggests that both ends of the political spectrum tap into moral ideas that fit with human nature, resting on evolved moral intuitions generated by our “righteous minds.” Perhaps surprisingly for an academic, he suggests that if anyone it’s liberals who discount certain values, such as in-group loyalty, purity, and authority, which a flourishing society cannot completely abandon. Liberals care about only harm and fairness, so they can’t fathom why anyone would place great moral weight on, say, loyalty to one’s own country.

Haidt and others think this is the key to getting along better. However, even if Haidt is right about how liberals and conservatives think about morality, understanding moral disagreements as grounded in fundamentally different moral values would presumably make disagreements more entrenched. As Jesse Prinz points out, this would make political debate across parties “a bit of a charade,” as one’s opponents must be viewed as either morally bankrupt or ignorant. But we shouldn’t underestimate the common moral ground we have and how often the sticking points are non-moral facts.

Consider abortion, still one of the most contentious issues in America. Liberals and conservatives tend to agree that we shouldn’t sacrifice a person’s life for mere convenience. Much of the disagreement is about when a fetus becomes a full-blown person, with basic inalienable rights. Conservatives tend to believe that life begins at conception. Many liberals instead say that, while a human organism may begin at conception, a person does not exist until at least the organism can suffer. If the abortion debate hinges greatly on when personhood begins, then this is not primarily a dispute about fundamental moral values.

Other moral debates likewise seem to boil down to non-moral facts. Liberals and conservatives can both value social stability, for example, but disagree about whether same-sex marriage is likely to erode it. The great opposition to human cloning is often due to misunderstanding the science (e.g. cloned individuals are not mindless servants or even exact copies of people, but rather very much like twins). Often people just have different beliefs about the likelihood of various threats (e.g. climate change, mass shootings, government take-over, terrorist attacks) and about the best ways to avoid harm (e.g. whether capital punishment deters crime). Other disputes stem from different religious beliefs about the nature and origin of the universe (consider the debate over creationism in schools) or about whether a practice (e.g. divorce, contraception, homosexuality, premarital sex) is unacceptable to one’s deity.

Conservatives and liberals might seem to exhibit fundamentally different values concerning social programs. But often these disputes turn on disagreements about the severity of lingering racism or innate differences between the sexes. These beliefs effect, for example, the heated debates about the killings of unarmed black men (in Ferguson and elsewhere), welfare, and equal pay for equal work. Conservatives care about fairness and people’s wellbeing, but the opposition to special treatment for certain groups often seems driven by the non-moral belief that racism is no longer a substantial problem in America. (This is precisely what led the Supreme Court last year to overturn a core part of the Voting Rights Act.)

The point is this. If moral disputes often turn on disagreements about non-moral facts, then we are in a better position to get along. First, with common moral ground, we can focus on the arguably more tractable issues. Second, even for those numerous disagreements that will undoubtedly remain, a proper perspective on one’s opponents can aid in compromise. No longer believing the opposing side is evil or insane should make one much more willing to debate the issue in a civilized manner and concede certain points, even without agreement on all the non-moral facts of the case. Compromise, not agreement, is often the more attainable goal, especially given our stubborn nature. (Congress, take note.)

Perhaps the primary prescription is humility. Whether we should increase taxes on the rich or whether disadvantaged groups are entitled to social services, it all depends a great deal on complicated historical, sociological, and economic facts that are difficult to settle. Deferring to experts is often required, then, even if that means the moral verdict may be influenced by our best science, for example.

So this Thanksgiving remember that, just like you, your fellow citizens on the other side of the issue also want to do what’s right. And by and large they value life, liberty, fairness, happiness, family, kindness, respect, honesty, property rights, desert, justice, just like you. More than half the battle is figuring out how these values apply to the complex issues of our day. We should expect in advance that reasonable people may disagree.


Josh May
Department of Philosophy
University of Alabama at Birmingham

Measurement: Do we take it or make it?

In May we took a perspective on measurement theory in the philosophy of science. The current snapshot of measurement theory is that measurement is representational.

The key aspects of representation through measurement are:

• Measurement tells us what things look like (from a specified vantage point), rather than what they are like. 
• Measurement involves selective perspectival input. 

Van Fraassen uses the analogy of visual perspective to illustrate (1) and (2). Think of measurement as taking a vantage point on some phenomenon. For example, when we measure evolutionary processes, the scientist decides the perspective (e.g. the view from the gene, epigene, individual, population, niche, etc.).

This view, which I will refer to as the ‘perspectival view,' is informative for analyzing scientific practice. It accounts for the imperfections and limitations of our representational activities while grounding a certain kind of objectivity. The phenomena are presumed to remain stable, even if our theories and practices may vary in successfully representing those phenomena. This is the basis for the appearance-reality distinction discussed in ‘Explanation and Illusion’. However, the perspectival view of measurement places too much focus on the outcome of passive representation, and not enough on the process of measurement.

Van Fraassen is wrong to use perspectival art as an analogy to measurement. Taking a perspective is a passive activity. Much of measurement is not passive. It is messy in terms of the type of interaction that takes place. And, a theory of measurement should account for this interactivity.

Here’s a simple example to bring our attention to measurement interactivity:

How do you measure the boiling point of water? You stick a thermometer in the sample, and, get a reading. This seems simple and representational: the value on the thermometer represents the quantity of temperature. But this perspectival story leaves out the interaction involved in the measurement process.

According to Hasok Chang (2004), the history of standardizing fixed points in thermometry is a history of “manufacturing” fixed points. The point at which water boils depends on the material conditions within our measurement set-ups. Initially it was discovered that boiling point varies with differences in atmospheric pressure (2004, 15). Additionally, the presence of dissolved air in water produced ebulliation-like phenomena at 101.9 degrees C (2004, 19). However, purged water (water without dissolved air) was measured to behave in a phenomenologically similar manner at much higher temperatures (as high as 140 degrees C). According to Chang, scientists began to focus on samples of water without dissolved air (2004, 16-19). Chang presents anecdote about how De Luc walked, slept, ate, etc., for 4 weeks straight all while shaking a tube of water to purge it of the dissolved air. De Luc’s dedication to manipulating the conditions of measurement serves as a good illustration of the care with which the measurement interactions have to be chosen in order to have a stable, reproducible phenomenon. It also illustrates how sensitive the phenomenon is to the interaction between conditions of the measurement set-up.

Now, for the difficult philosophical question: Is this type of measurement representational, or, is it productive? In each of the measurement set-ups, the boiling point is taking shape with the measurement conditions. In other words, the set-up provides the conditions for the production (and re-production) of the phenomenon. This type of language doesn’t have to “sound” quantum mechanic-y or constructivist. We do not have to discuss a pot of water boiling in the forest. In fact, we need not say anything about pre-measurement values and post-measurement results. All we have to focus on is that the interaction of the conditions for measurement matter to the production of the phenomenon. In simple terms, change the conditions, change the phenomenon. Whether you choose to remain a representationalist or a productivist, one thing we have to consider is that much of the measurement process occurs within the measurement set-up and execution. The final representational step, the measurement outcome, is a small slice of the process. A robust theory of measurement should account for the interactions in this process.

While we’re doing some revision, let’s try out a more adequate art analogy for measurement—one that focuses on interaction rather than passive perspective. The art process of Jackson Pollock is a good starting point.

Pollock numbered his paintings so that people would look at them without searching for representational elements in the names of his paintings (Karmel and Varnedoe 1999). For Pollock, the work of art is not a representation of a phenomenon (1999, 68-69). Rather, it is the phenomenon, which is produced by the interactions that take place in the painting set-up (1999, 99). Pollock was resistant to representation in art. He was also resistant to the view that artists should paint things “out in nature”: “When asked whether he painted from nature, Pollock replied: “I am nature”” (1999, 253). Pollock’s painting set-up and the interaction that occurred within this set-up can be summarized as follows: First, paint was carefully selected to have the proper viscosity. Pollock used gloss enamel paint rather than oil-based paint. The paint was sometimes diluted to have little textural effect, and at other times thickened. He used sticks, worn out brushes, and basting devices that looked like giant fountain pens. 

Pollock also used raw, unstretched canvas in order to be able to perform full-body painting (1999, 72). The painting resulted from the interaction that took place within the painting set-up. Moreover, it is fair to say that it is difficult to appreciate the work of art without looking at this process of interaction. As part of the painting set-up, Pollock is interacting with other elements of the set-up to produce the phenomenon. In interviews Pollock describes being “in” his painting when making it (1999, 17). This analogy puts emphasis on the messy interaction that occurs in measurement. It is, however, important to note that the analogy is incomplete. In measurement, we want repeatable, reproducible phenomena. In painting, we want unique, authentic productions. I welcome all of our fellow DR-ers to manufacture a better analogy.


Work Cited:

Chang, Hasok. (2004). Inventing Temperature. Oxford: Oxford University Press.

Karmel, Pepe, & Varnedoe, K. (1999). Jackson Pollock: interviews, articles, and reviews. New York:Museum of Modern Art : Distributed by H.N. Abrams. 

van Fraassen, B. C. (2009). Scientific representation: Paradoxes of perspective. Oxford: Oxford University Press.

Vadim Keyser

Department of Philosophy

Sacramento State

Deadly Cows and Living Inside of Whales

Humans aren’t good at estimating probabilities. My sense for how likely something is usually arises from a kind of intuitive hunch about it that comes from the comfort level of the idea. If it feels cognitively uncomfortable, like if someone says, “Eggplants usually grow to weigh more than 20 lbs.,” I’m skeptical. But if it feels familiar or comfortable in my head, like, “Justin Beiber actually can’t play any musical instruments,” I’m inclined to accept it.

Behavioral economists like Daniel Kahneman and Amos Tversky have identified a bias that lives here. It’s called Availability Bias. Formally, the idea is that we are prone to mistake the ease with which something is called to mind, or the subjective comfort we have with an idea, for its objective probability. In one famous experiment, subjects were asked to estimate whether there are more English words that begin with “r” or have “r” as the third letter. Since calling words to mind that start with “r” is easy, most people answer that those are more common. But being able to readily recall words that start with the letter is a quirky feature of the human brain. We’re good at that, just like we’re pretty good at memorizing 7 digit strings of numbers like phone numbers, but 13 digit strings are much harder. Our brains are not well-equipped to do a systematic search of words with “r” in the third position, but we mistake that subjective difficulty as representative of their real frequency in the world.

The mistake comes out in lots of places. During Shark Week on the Discovery Channel, people are more afraid of shark attacks and estimate their likelihood as higher. Cows, it turns out, are the real menace to society. You are more than 20 times more likely to be killed by cows than by a shark. People think that zombies and vampires are more plausible now than they did several decades ago when they weren’t such a large part of pop culture. We all drive more conscientiously for the weeks after someone we know has been in a serious car wreck, and we watch our salt intake more closely when a relative has recently had a heart attack.

Now I’m going to suggest something that may offend. Why is it that so many people who are otherwise quite reasonable, and who would never believe similar claims out of context, claim to actually believe outlandish stories like Jonah and the Whale, the Genesis Creation story, the claim that Noah lived to be 900 years old, the story of Joseph Smith being visited by an angel who gave him the book of Mormon, the story of Mohammed being visited by angel who gave him the Koran, and Paul having a seizure and hearing the voice of God? If comparable stories were offered with different, unfamiliar details, I think most Americans would be skeptical at the very least. In fact, if you’re the typical mainstream American Christian, you are skeptical about the Mohammed story and the Joseph Smith story. But tens of millions, perhaps hundreds of millions of Americans take these claims to be true. I take it as pretty obvious that they are not. And I think it’s availability bias that has artificially elevated the plausibility of them in people’s minds. How did these stories become so available to so many people? When people hear such stories over and over, hundreds or thousands of times through childhood and into adulthood, and when the stories are treated as momentous, or even historical, it has the same effect on our probability judgments as Shark Week. When we see portrayals, reread the stories, and hear them repeated and treated with reverence thousands or tens of thousands of times, they come to feel familiar, vivid, and, ultimately, probable. The readiness with which the idea can be called to mind gets mistaken for its reality. I don’t think it is too much to suggest that our widespread acceptance of the story of Jesus’ return from the dead can be attributed, at least in part, to availability bias too.

I’m not offering an argument here for why I think these claims are false. I think you’ll already agree with me in the abstract that it is exceedingly unlikely that a person could survive for several days after being eaten by a whale. And humans do not, as far as we know, ever live much past 100 years, even with all of the benefits of modern medicine and health research. And the religious example aside, you’ve never heard a single plausible report of a human actually being biologically dead and then returning to normal living function after three days. You already share my skepticism about other claims like these. In other contexts, you already agree that such claims are outrageous. So why is it that the religious examples don’t feel more cognitively uncomfortable? Availability bias.

Here’s a meta-level way to think about your own disposition to make this mistake (and lots of others). We all possess nervous systems that do a pretty good job of solving some problems. But we know that when we put them in certain environments, or frequently expose them to certain kinds of stimuli, like mythological stories, those exposures skew the system’s capacity to sort true from false, probable from improbable, reasonable from unreasonable. And knowing that we are built that way facilitates our efforts to compensate and correct for the bias. 

Matt McCormick

Department of Philosophy

Sacramento State

Biased science

Most people think of bias in personal terms, but in science the most pernicious forms of bias are institutional, not personal. They are not, in other words, the result of rogue scientists fudging their findings to support their pet theories. Rather, they are the result of biased processes for publishing scientific findings that are, in fact, perfectly legitimate.

The key point to understand is this: For any scrupulously conducted scientific study or experiment, there is always some chance that its findings are wrong. Reporting bias and publication bias are effectively institutional preferences for selecting the results of just such studies and experiments for publication, while thousands of others that find no such results never see the light of day.  Both forms of bias are rampant in science, and their causes are many.

Social sciences suffer from major reporting bias, because most negative results are not reported. Franco, et al. (2014) conclude that out of 221 survey-based experiments funded by the National Science Foundation from 2002 to 2012, two-thirds of those with results that did not support a tested hypothesis were not even submitted for publication. Strong results were 60% more likely to be submitted and 40% more likely to be published than null results.  Only 20% of those with null results ever appeared in print. (See graphic here.)

It is not much better in clinical studies. Reporting bias leads to over-estimating or under-estimating the effect of a drug intervention, and reduces the confidence with which evaluators can accept a test result or make judgments about the significance of such results. For any medicines or medical devices regulated by the FDA, posting at least basic results to ClinicalTrials.gov is mandatory within one year of study completion, but compliance is low. A 2013 estimate puts the failure to publish or post basic results at over 50%. No study results get reported at all in 78% of 171 unpublished but registered studies completed before 2009.

Reporting bias infects the evidence evaluation process for randomized controlled trials (RCTs), the basic experimental design for testing scientific hypotheses. That RCTs have limits is well-known. Each requires a large number of diverse participants to achieve statistical significance. Often the random assignment of participants or sufficient blinding of subjects and investigators is not feasible, and lots of hypotheses cannot be tested due to ethical concerns. For instance, sham or ineffective treatments given to seriously suffering patients harm those who might otherwise benefit. We also shouldn’t do an antisocial behavior RCT in a simulated prison environment and to get accurate data. When RCTs are ethical and well-designed, the critical opinions of experts is crucial, since a risk of bias is always present.

Peer-review assesses the value of RCTs, but the effectiveness of this process is compromised when relevant data are missing.Without effective peer-review we consumers of science and its applications have no coherent reason to believe what scientists tell us about the value of medical interventions or the danger of environmental hazards. 

Not sharing, publishing, or making accessible negative results has numerous bad consequences. Judgments based on incomplete and unreliable evidence harms us. We probably accept many inaccurate scientific conclusions. Ioannidis (2005), for example, contends that reporting bias results in most published research findings being false.

Reporting bias harms participants in studies who are exposed to unnecessary risks. Society fails to benefit from the inclusion of relevant RCTs with negative results in peer-review evaluations. Researchers waste time and money testing hypotheses that have already been shown to be false or dubious. Retesting drug treatments already observed to be ineffective, or no more effective than a placebo squanders resources. Our scientific knowledge base lacks defeaters that would otherwise undercut flawed evidence and false beliefs about the value of a drug. RCTs and the peer-review process are designed to detect these but fail due to selective reporting.

RCT designs are based on prior research findings. When publishers, corporate sponsors, and scientists are unaware of previous negative results and prefer positive to negative results, many hypotheses with questionable results worthy of further testing are overlooked. Since all trials do not have an equal chance of being reported, datasets skew positive (erroneously) and this affects which hypotheses scientists choose to examine, accept, or reject.

Mostly positive results in the public record make the effect of a drug with small or false positive effects appear stronger than it actually is, which in turn misleads stakeholders (patients, physicians, researchers, regulators, sponsors) who must make decisions about resources and treatments on the basis of evidence which is neither the best nor available. Studies of studies (meta-analyses) reveal this phenomenon with popular, widely prescribed antiviral and antidepressant medications. Ben Goldacre tells a disturbing story about the CDC, pharmaceutical companies and antivirals.

Link to TED Video

A meta-analysis uses statistical methods to summarize the results of multiple independent studies. RCTs must be statistically powerful enough to reject the null hypothesis, i.e., the one researchers try to disprove before accepting an alternative hypothesis. Combining RCTs into a meta-analysis increases the power of a statistical test and resolves controversies arising from conflicting claims about drug effects. In separate meta-analyses from 2008 of antidepressant medications (ADMs) Kirsch,et al., and Turner, et al., find only marginal benefits over placebo treatments. When unpublished trial data get added back to the dataset, the great benefit previously reported in the literature becomes clinically insignificant. This is disturbing news: For all but the most severely depressed patients ADMs don’t work, and they may appear to work in the severely depressed because the placebo stops working, which magnifies the apparent affect of the ADM compared to placebo-controls.

Even when individual scientists behave well, the scientific establishment is guilty of misconduct when it fails to make all findings public.  In order for science to be the self-correcting, truth-seeking process it clams to be, we need access to all the data.

Scott Merlino
Department of Philosophy
Sacramento State