Edge 204 — March 5, 2007
(5,370 words)

By Eric R. Kandel

In a larger sense, social cognition is an extreme example of a broader issue in biology of mind, and that is social interaction in general. Even here we are beginning to make some rather remarkable progress. Cori Bargmann, a geneticist at the Rockefeller University, has studied two variants of a worm called C elegans, that differ in their feeding pattern. One variant is solitary and seeks its food alone; the other is social and forages in groups. The only difference between the two is one amino acid in an otherwise shared receptor protein. If you move the receptor from a social worm to a solitary worm, it makes the solitary worm social.

[...more below]

Darwin's God
By Robin Marantz Henig

In the world of evolutionary biology, the question is not whether God exists but why we believe in him. Is belief a helpful adaptation or an evolutionary accident?

God has always been a puzzle for Scott Atran. When he was 10 years old, he scrawled a plaintive message on the wall of his bedroom in Baltimore. "God exists," he wrote in black and orange paint, "or if he doesn’t, we’re in trouble." Atran has been struggling with questions about religion ever since — why he himself no longer believes in God and why so many other people, everywhere in the world, apparently do. ...

Call it God; call it superstition; call it, as Atran does, "belief in hope beyond reason" — whatever you call it, there seems an inherent human drive to believe in something transcendent, unfathomable and otherworldly, something beyond the reach or understanding of science....

...The magic-box demonstration helped set Atran on a career studying why humans might have evolved to be religious, something few people were doing back in the ’80s. Today, the effort has gained momentum, as scientists search for an evolutionary explanation for why belief in God exists — not whether God exists, which is a matter for philosophers and theologians, but why the belief does.

This is different from the scientific assault on religion that has been garnering attention recently, in the form of best-selling books from scientific atheists who see religion as a scourge. In "The God Delusion," published last year and still on best-seller lists, the Oxford evolutionary biologist Richard Dawkins concludes that religion is nothing more than a useless, and sometimes dangerous, evolutionary accident. "Religious behavior may be a misfiring, an unfortunate byproduct of an underlying psychological propensity which in other circumstances is, or once was, useful," Dawkins wrote. He is joined by two other best-selling authors — Sam Harris, who wrote "The End of Faith," and Daniel Dennett, a philosopher at Tufts University who wrote "Breaking the Spell." The three men differ in their personal styles and whether they are engaged in a battle against religiosity, but their names are often mentioned together. They have been portrayed as an unholy trinity of neo-atheists, promoting their secular world view with a fervor that seems almost evangelical.

Lost in the hullabaloo over the neo-atheists is a quieter and potentially more illuminating debate. It is taking place not between science and religion but within science itself, specifically among the scientists studying the evolution of religion. These scholars tend to agree on one point: that religious belief is an outgrowth of brain architecture that evolved during early human history. What they disagree about is why a tendency to believe evolved, whether it was because belief itself was adaptive or because it was just an evolutionary byproduct, a mere consequence of some other adaptation in the evolution of the human brain.

Which is the better biological explanation for a belief in God — evolutionary adaptation or neurological accident? Is there something about the cognitive functioning of humans that makes us receptive to belief in a supernatural deity? And if scientists are able to explain God, what then? Is explaining religion the same thing as explaining it away? Are the nonbelievers right, and is religion at its core an empty undertaking, a misdirection, a vestigial artifact of a primitive mind? Or are the believers right, and does the fact that we have the mental capacities for discerning God suggest that it was God who put them there?

In short, are we hard-wired to believe in God? And if we are, how and why did that happen?

[ED. NOTE: Further reading on Edge: Scott Atran, Richard Dawkins, Sam Harris, Daniel C. Dennett, Noam Chomsky, Gregory Bateson, Pascal Boyer, Paul Bloom, Stephen Jay Gould, Jesse Bering.


March 4 , 2007

At Home Before and Behind the Curtain
By David Colman

THE letters WYSIWYG may have helped immeasurably in closing the gap between the computer and the real world, letting you know that when you look at a properly formatted document on screen, what you see is what you get.

That may be good enough for your résumé, but not for Richard Foreman, who in his 39 years as the director of the Ontological-Hysteric Theater in the East Village has steadfastly maintained an artistic vision in which WYS is not in the least WYG. So do not go to "Wake Up Mr. Sleepy! Your Unconscious Mind Is Dead!" by Mr. Foreman expecting art to mirror life. ....

..."Too much theater arranges thing so that people are led on a journey that reinforces the emotional habits of their lives," Mr. Foreman said, sitting in the book-infested SoHo loft he has shared with his wife since they bought it for a song in 1970. "For many years I’ve said that stories hide the truth." His preference, he said, for his own life and his own brand of theater, is "hovering on the edge of understanding, waiting to see what direction it goes in." ...

..."The moment things get too slick or well done, it becomes a system, and then you’re imprisoned by it. This way it’s a little awkward, but it makes me hover in the realm of possibility, which is where I like to be."


03 March 2007


Ivan Semeniuk

Audio: We devote a full episode of our weekly podcast, SciPod, to exploring Marc Hauser's work on the "moral organ" and what it means to our notions of justice and fair play. Listen to it here (mp3 format).

In a hospital emergency room, five critically ill patients desperately need organ transplants. A healthy man walks in. Should the doctors remove his organs to save the sick five? Most people will respond in milliseconds with a resounding "No way". Now imagine an out-of-control train about to run down five workers standing on the track. There's a fork ahead, and throwing a switch could divert the train to another line on which there is only one worker. It's the same question - should we sacrifice the one to spare the other five? - yet most of us would say "yes" just as quickly. How do we make these lightning moral judgements? In his latest book, Marc Hauser argues that this ability is evidence that we are born with an innate moral faculty. He sat down to talk good and evil with Ivan Semeniuk. ...


March 3, 2007

Books on Atheism Are Raising Hackles in Unlikely Places
By Peter Steinfels

Hey, guys, can't you give atheism a chance?

Yes, it is true that "The God Delusion" by Richard Dawkins has been on The New York Times best-seller list for 22 weeks and that "Letter to a Christian Nation" by Sam Harris can be found in virtually every airport bookstore, even in Texas.

So why is the new wave of books on atheism getting such a drubbing? The criticism is not primarily, it should be pointed out, from the pious, which would hardly be noteworthy, but from avowed atheists as well as scientists and philosophers writing in publications like The New Republic and The New York Review of Books, not known as cells in the vast God-fearing conspiracy. ...

Scientists and philosophers criticize two authors as lacking knowledge of theology.

...Finally, these critics stubbornly rejected the idea that rational meant scientific. "The fear of religion leads too many scientifically minded atheists to cling to a defensive, world-flattening reductionism," Mr. Nagel wrote.

"We have more than one form of understanding," he continued. "The great achievements of physical science do not make it capable of encompassing everything, from mathematics to ethics to the experiences of a living animal. We have no reason to dismiss moral reasoning, introspection or conceptual analysis as ways of discovering the truth just because they are not physics."

So what is the beleaguered atheist to do? One possibility: take pride in the fact that this astringent criticism comes from people and places that honor the honest skeptic’s commitment to full-throated questioning.


March 1, 2007


What We Believe But Cannot Prove: Today's Leading Thinkers in the Age of Uncertainty;
Book review
By Kenneth W. Krause

Those who wonder what cutting-edge scientists might ponder outside of their classrooms and laboratories need wonder no more. In What We Believe But Cannot Prove, "intellectuals in action" speculate on the frontiers of science, both hard and soft (p. ix). Skeptics, however,should not be deceived by the title. An ample majority of the more than 100 teasingly short essays included will sate the intellect's appetite for both facts and reasoned theory. John Brockman's new collection features the world's most celebrated and respected scientists and their musings on everything from human pre-history to cosmology and astrophysics, from evolution to extraterrestrial intelligence, and from genetics to theories of consciousness.

Regardless, What We Believe But Cannot Prove offers an impressive array of insights and challenges that will surely delight curious readers, generalists and specialists alike. Science is intimidating for the vast majority of us. But John Brockman has grown deservedly famous in recent years for his ability to lure these disciplines and their leading practitioners back to Earth where terrestrials are afforded all-too-rare opportunities to marvel at the intellectual and creative magnificence of science in particular, and at our species' immeasurable potential in all pursuits more generally.


28 February 2007

Amanda Gefter

Even after decades of research into artificial intelligence, machines still don't think like human beings. Marvin Minsky, the discipline's founding father, refuses to give up hope. His solution is to make machines more emotional - and feelings, he says, are simpler to model than rational thought. He talks to Amanda Gefter about the need for emotional machines, the inner workings of the human brain, and the future of AI

Many people are disappointed at the lack of progress in AI since the 1980s. Why so little headway? In the early years of computing, we found it easy to program machines to solve problems that people regarded as difficult, such as designing efficient aeroplane wings, playing chess, or diagnosing heart attacks. But none of those programs could do the things that people regard as relatively easy - such as making a bed, babysitting or understanding a story from a children's book.It is much the same today. Each program has only one specialised skill, and when anything happens that isn't expected the computer produces absurd results or gets stuck in an endless loop.In contrast, humans rarely get totally stuck because we have many different ways to deal with each situation or job. So whenever your favourite method fails, you can usually find a different approach. For example, if you get bored with one particular job, you can try to persuade someone else to do it or get angry with those who assigned it to you. We might call such reactions emotional, but they can help us deal with the problems we face.

You call your new book The Emotion Machine. Is that because you're convinced that computers need emotions to help them think in the same way as people? Yes and no. The goal of the book is to try to explain what gives people their unique resourcefulness so that we can make our machines more versatile. We all grow up with the idea that emotions and thinking are quite different things, that thinking is basically simple because it is mainly a matter of rational logic, whereas emotions are far more complex and mysterious. I take the opposite view: that emotional states are usually simpler than most of our other ways to think.


February 27, 2007

J. Craig Venter: God Didn't Have Computers

[click on image]

Craig Venter explains that he can do a better job with genetics than God because he uses a computer.


February 18, 2007

SCIENTIST; Celebrating Those Who Leave Some of Themselves in Their Work

By Cynthia Magriel Wetzler

CLIFFORD PICKOVER likes to contemplate realms beyond our known reality. A futurist and science writer with a Ph.D. in molecular biophysics and biochemistry from Yale University, he is the author of 37 books on topics as diverse as computers and creativity, art, mathematics, human behavior and intelligence, religion, time travel and alien life. ...

...'After you die, will the world remember anything you did?'' asks the book at its start. Among the individuals celebrated in the book are the author Truman Capote and the composer John Cage, who achieved, Mr. Pickover said, a kind of immortality by leaving some of themselves behind in their work. Capote created the nonfiction novel, ''In Cold Blood,'' in which true facts are told in story form, dramatically reinventing the scope of nonfiction writing. Cage composed a silent symphony. Mr. Pickover calls these individuals ''chameleons.''

''Do you know what chameleons are?'' he asked in an interview at his home in Yorktown Heights. ''They are lizards famous for their ability to change their skins to an amazing variety of colors. They are odd creatures with eyes that can survey their world with nearly 360-degree vision.''

The people in his book are chameleons because they looked in many directions, were constantly changing, and flaunted their flamboyant colors, he said. All creative people are lateral thinkers, Mr. Pickover said, able to let their minds and imaginations drift from the mainstream to the tributaries where serendipity may await. ''I sometimes aspire to being one of the chameleons,'' he said. ''In my book I often have one mental eye on a person while the other is considering related quirky facts.''


March 1 , 2007

SF Writer Rudy Rucker: Everything Is Computation
By R.U. Sirius

In this interview, Rucker leads us through complex, technology-rich, multi-leveled worlds that teach us about how the world works through the eyes of a mathematician, a scientist, and a humorist.

RU: There’s been some talk about parallel universes within the context of science and math and so forth. And I’m sure you have some thoughts and can tell us a little bit about how people have thought about this in the actual world.

RR: There are a number of theories. A theory that I’ve drawn on recently comes from a scientist named Lisa Randall. She wrote an interesting book called Warped Passages: Unraveling the Mysteries of the Universe’s Hidden Dimensions. There’s this problem in physics with the fact that gravity is weaker than the other kinds of natural forces. Its basic intensity is dialed down really low. And physicists wonder — why isn’t it similar? And she has this explanation. Maybe there’s this other brane, as they call it – there’s a membrane, and part of reality is over there. And somehow it’s siphoning off some of our gravity. I like that idea of parallel universes. It’s sort of a specialized physics use of the parallel universe idea. The one that’s used in more fiction is the old quantum mechanical model that whenever something could randomly go this way or that way, maybe it goes both ways, and then both the universes exist.


In a larger sense, social cognition is an extreme example of a broader issue in biology of mind, and that is social interaction in general. Even here we are beginning to make some rather remarkable progress. Cori Bargmann, a geneticist at the Rockefeller University, has studied two variants of a worm called C elegans, that differ in their feeding pattern. One variant is solitary and seeks its food alone; the other is social and forages in groups. The only difference between the two is one amino acid in an otherwise shared receptor protein. If you move the receptor from a social worm to a solitary worm, it makes the solitary worm social.

By Eric R. Kandel


In keeping with the theme of this year's Question: "What Are You Optimistic About", Edge asked neuroscientist and Nobel Laureate Eric Kandel for a sampling of recent developments in neuroscience that inspire his optimism. "in a field as broad and as deep as neuroscience," he writes, "it is difficult to select simply four contributions. I therefore consider this a sampling of the contributions that drive my optimism rather than a true selection of the top four. Moreover, I have simplified the task by dividing the field into four areas: Molecular Neuroscience, Systems Neuroscience, Cognitive Neuroscience, and Neuroscience of Psychiatric Disease."


ERIC R. KANDEL is University Professor at Columbia University in the Department of Biochemistry and Molecular Biophysics and in the Department of Psychiatry at Columbia and a Senior Investigator at the Howard Hughes Medical Institute. He is the recipient of the Nobel Prize in Physiology or Medicine, 2000. He is the author In Search of Memory: The Emergence of a New Science of Mind.

Eric Kandel's Edge Bio Page


I list here four major accomplishments in neuroscience in the past year that have inspired me.  I begin by saying that in a field as broad and as deep as neuroscience, it is difficult to select simply four contributions. I therefore consider this a sampling of the contributions that drive my optimism rather than a true selection of the top four.  Moreover, I have simplified the task by dividing the field into four areas: Molecular Neuroscience, Systems Neuroscience, Cognitive Neuroscience, and Neuroscience of Psychiatric Disease.

Molecular NeuroscienceThe discovery of the double helix by Watson and Crick in 1952 gave rise to a central dogma in molecular biology, according to which genes (encoded in DNA) give rise to messenger RNAs which encode proteins, the workhorses of the cell. The discovery a few years ago of microRNAs, a class of small non-coding genetic elements that control the translation of target messenger RNAs, highlighted a new layer of gene regulation downstream from DNA.  MicroRNAs have been described in numerous species across the evolutionary spectrum, and there are thought to be about 500 different microRNAs encoded in the human genome.  Although microRNAs are very short (only 21 nucleotides long), each is thought to bind to a number of different messenger RNA targets. Thus they may have a very profound effect on gene action in both the human brain and in simpler experimental animals. The existence of microRNAs has been known for several years but only recently has it become recognized that they are particularly important in the nervous system where they serve, among other functions, to regulate synaptic strength—the effectiveness with which one neuron communicates with another.

In the year 2006, two important papers emerged in this area. The first one by Ashraf and Kunes revealed that a microRNA regulates the synthesis of proteins locally at  synapses in the Drosophila brain following learning and that microNRAs are essential regulatory components at the synapse of memory storage. A second example is from Michael Greenberg’s laboratory, where it was discovered that a brain-specific microRNA is important for the development of dendritic spines in hippocampal neurons. They demonstrated that a particular microRNA inhibits development and maturation of the spine, which is a preferential site of contact between neurons that form a synapse together.  In both cases these microRNAs have turned out to be very important for the formation of synapses and for synaptic plasticity. Thus, these discoveries open up a new molecular treasure chest, a new level of regulation that had not been appreciated.

Systems Neuroscience.  In the late 1960s and 1970s, David Hubel and Torsten Wiesel gave us the initial insight as to how the early input stages of the cerebral cortex process and transform the incoming visual messages. This gave us our first insight of how an image—say, an image of a face or a landscape—is first deconstructed and then reconstructed in the brain. In all living creatures, from simple animals to people, knowledge of space is central to behavior. We live in space, we move through it, we explore it, and we defend it. Space is not only important but it is fascinating because unlike other sense modalities, it is not analyzed by special sensory organs like the eye for seeing or the ear for hearing. This has raised the question, How is space represented in the brain? Immanuel Kant, the great German idealist philosopher argued that the ability to represent space is built into the mind. He argued that people are born with principles of ordering space and time. These are part of what he called the categorical imperatives. When other sensations are elicited such as visual sensations of objects, or auditory sensations of melodies, or touch experiences, they are interwoven automatically in specific ways with space and time. We remember people and events in a spatial context. Because we do not have a special organ dedicated to space, the representation of space is the cognitive sensibility par excellence. It is the binding problem write large.  The brain must combine inputs from several different sensory modalities and then generate a complete internal representation that does not depend exclusively on one input. The brain commonly represents information about space in many areas in many different ways and the properties of each representation vary according to purpose. 

John O’Keefe, working in England, first discovered in 1971 that the hippocampus of the rat contains a multisensory representation of space. O’Keefe found that when an animal walks around in an enclosure, some cells in the hippocampus fire action potentials, and they do so only when the animal moves in a particular location. Other cells fire when the animal moves in another point in spoace. In this way the brain breaks down its surroundings into small overlapping areas, similar to a mosaic, each represented by activity in specific cells in the hippocampus. The internal map of space develops within minutes of the rat’s entrance into a new environment.

But in many higher order areas, we know little about the nature of the transformations. The perception of space is a particularly vexing example because it is mediated by the combination of several sense modalities. During the past year we have learned from the work of May-Britt Moser and Edvard Moser of Norway how spatial information is transformed by the hippocampus. In experimental animals, particularly the mouse, one of the most important sensory representations in the hippocampus—a structure important for memory storage—is the representation of external space within which the animal is placed. It is now clear that the initial representation of space occurs not in the hippocampus proper but in an association cortex—the entorhinal cortex—that serves as the input stage to the hippocampus. The Mosers have found that the entorhinal cortex already has a unique form of spatial representation encoded by grid cells. These grid cells convey to the hippocampus, via the convergence of several grid cells onto the hippocampal place cell, information about position, direction, and distance that is essential for navigation.

Cognitive Neuroscience. When you and I talk to one another, we not only know the contents of our own mind but we also have a sense of the content of what the other person is thinking and how they are reacting. We have, so to speak, a sense of the social expectations of the situation and the kinds of ideas that the conversation brings forth in the colleague with whom we are communicating. During the past year several important studies have localized aspects of this function in the cerebral cortex. First, Rebecca Saxe has found that there is a specific area in the brain at the junction between the temporal and parietal lobes that encodes aspects of the theory of mind. It becomes active when a person entertains ideas about another person’s possible responses to our actions. This new finding extends a series of important findings from Rizzolatti’s group in Italy which first showed that there are certain cells in the premotor areas of parietal cortex of the monkey that respond not only when a monkey picks up a peanut but also when the monkey sees another monkey or a human being pick up a peanut. These cells are called mirror cells because they respond not only to personal action but in an imitative way to the action of others. In addition to showing a cellular basis for a theory of mind, these cells also illustrate that the motor systems have cognitive function. Imaging experiments by Ramachandran have shown that this area is present in people, and that it appears to be disturbed in patients with autism.

In a larger sense, social cognition is an extreme example of a broader issue in biology of mind, and that is social interaction in general. Even here we are beginning to make some rather remarkable progress. Cori Bargmann, a geneticist at the Rockefeller University, has studied two variants of a worm called C elegans, that differ in their feeding pattern. One variant is solitary and seeks its food alone; the other is social and forages in groups. The only difference between the two is one amino acid in an otherwise shared receptor protein. If you move the receptor from a social worm to a solitary worm, it makes the solitary worm social. This is one of several examples in which changing a single gene alters the social behavior of an animal. Another example is male courtship behavior in Drosophila, which is an instinctive behavior that requires a critical protein called fruitless. Fruitless is expressed in slightly different forms, one in male flies and the other in female flies. Ebru Demir and Barry Dickson have made the remarkable discovery that when the male form of the protein is expressed in females, the females will mount and direct the courtship toward other females or toward males that have been engineered to produce a characteristic female odor. Dixon went on to show that the gene for fruitless is required during development for hardwiring the neural circuitry for courtship behavior and sexual preference.

Neuroscience of Psychiatric Disease.  A major source of optimism is the emergence of an empirical, evidence-based psychotherapy. There are now a number of excellent studies that show that mild to moderately severe depression, as well as fear-based anxiety disorders and obsessive-compulsive disorders, respond to different versions of psychotherapy that are designed to focus not on deep underlying conflict but on the management of specific symptoms. The best established of these is cognitive behavioral therapy, first introduced in the 1970s by Aaron Beck at the University of Pennsylvania.

In the late 1950s, when Beck began his investigations, depressive illness was commonly viewed as a form of introjected anger. Freud had argued that depressed patients feel hostile and angry toward someone they love. Because patients cannot deal with negative feelings about someone who is important, needed, and valued, they handle those feelings by repressing them and unconsciously directing them against themselves. It is this self-directed anger and hatred that leads to low self-esteem and feelings of worthlessness.

Beck tested Freud’s idea by comparing the dreams of depressed patients with those of patients who were not depressed. He found that depressed patients exhibited not more, but less hostility than other patients. In the course of carrying out this study and listening carefully to his patients, Beck found that rather than expressing hostility, depressed people express a systematic negative bias in the way they think about life. They almost invariably have unrealistically high expectations of themselves, overreact dramatically to any disappointment, put themselves down whenever possible, and are pessimistic about their future. This distorted pattern of thinking, Beck realized, is not simply a symptom, a reflection of a conflict lying deep within the psyche, but a key agent in the actual development and continuation of the depressive disorder. Beck made the radical suggestion that by identifying and addressing the negative beliefs, thought processes, and behaviors, one might be able to help patients replace them with healthy, positive beliefs. Moreover, one could do so independent of personality factors and the unconscious conflicts that may underlie them.

To test this idea clinically, Beck presented patients with evidence from their own experiences, actions, and accomplishments that countered, challenged, and corrected their negative views. He found that they often improved with remarkable speed, feeling and functioning better after a very few sessions. This positive result led Beck to develop a systematic, short-term psychological treatment for depression that focuses not on a patient’s unconscious conflict, but on his or her conscious cognitive style and distorted way of thinking.

To evaluate systematically the effectiveness of this mode of therapy, Beck and his associates initiated controlled clinical trials comparing cognitive behavioral therapy with placebo and with antidepressant medication. They found that cognitive behavioral therapy is as effective as antidepressant medication in treating people with mild and moderate depression; in some studies, it appeared superior at preventing relapses. In later controlled clinical trials, cognitive behavioral therapy was successfully extended to anxiety disorders, especially panic attacks, post-traumatic stress disorders, social phobias, eating disorders, and obsessive-compulsive disorders.

What was next needed is a biological approach to psychotherapy. Until quite recently, there have been few biologically compelling ways to test psychodynamic ideas or to evaluate the efficacy of one therapeutic approach over another. A combination of effective short-term psychotherapy and brain imaging may now give us just that—a way of revealing both mental dynamics and the workings of the living brain. In fact, if psychotherapeutic changes are maintained over time, it is reasonable to conclude that different forms of psychotherapy lead to different structural changes in the brain, just as other forms of learning do.

The idea of using brain imaging to evaluate the outcome of different forms of psychotherapy is not an impossible dream, as studies of depression and obsessive-compulsive disorder have shown. Helen Mayberg had earlier found that Area 25 in the cerebral cortex is overactive in depressed patients. She then went on to find that this overactivity is reversed by cognitive behavioral therapy if, and only if, the therapy is successful. Obsessive-compulsive disorder has long been thought to reflect a disturbance of the basal ganglia, a group of structures that lies deep in the brain and plays a key role in modulating behavior. One of the structures of the basal ganglia, the caudate nucleus, is the primary recipient of information coming from the cerebral cortex and other regions of the brain. Brain imaging has found that obsessive-compulsive disorder is associated with increased metabolism in the caudate nucleus. Lewis R. Baxter, Jr. and his colleagues at the University of California, Los Angeles have found that obsessive-compulsive disorder can be reversed by cognitive behavioral psychotherapy. It can also be reversed pharmacologically by inhibiting the reuptake of serotonin. Both the drugs and psychotherapy reverse the increased metabolism of the caudate nucleus.

Short-term psychotherapy now comes in different forms and brain imaging may provide a scientific means of distinguishing among them. If so, it may reveal that all effective psychotherapies work through the same anatomical and molecular mechanisms. Alternatively and more likely, imaging may show that psychotherapies achieve their goals through distinctly different mechanisms in the brain. Psychotherapies are also likely to have adverse side effects, as drugs do. Empirical testing of psychotherapies could help us maximize the safety and effectiveness of these important treatments, much as it does for drugs.  It could also help predict the outcome of particular types of psychotherapy and would direct patients to the ones most appropriate for them.