robert_trivers's picture
Evolutionary Biologist; Professor of Anthropology and Biological Sciences, Rutgers University; Author, Wild Life: Adventures of an Evolutionary Biologist
The Science of Self-deception Requires a Deep Understanding of Biology

When I first saw the possibility (some 30 years ago) of grounding a science of human self-deception in evolutionary logic (based on its value in furthering deception of others), I imagined joining evolutionary theory with animal behavior and with those parts of psychology worth preserving. The latter I regarded as a formidable hurdle since so much of psychology (depth and social) appeared to be pure crap, or more generously put, without any foundation in reality or logic.

Now after a couple of years of intensive study of the subject, I am surprised at the number of areas of biology that are important, if not key, to the subject yet are relatively undeveloped by biologists. I am also surprised that many of the important new findings in this regard have been made by psychologists and not biologists.

It was always obvious that when neurophysiology actually became a science (which it did when it learned to measure on-going mental activity) it would be relevant to deceit and self-deception and this is becoming more apparent every day. Also, endocrinology could scarcely be irrelevant and Richard Wrangham has recently argued for an intimate connection between testosterone and self-deception in men but the connections must be much deeper still. The proper way to conceptualize the endocrine system (as David Haig has pointed out to me) is as a series of signals with varying half-lives which give relevant information to organs downstream and many such signals may be relevant to deceit and self-deception and to selves-deception, as defined below.

One thing I never imagined was that the immune system would be a vital component of any science of self-deception, yet two lines of work within psychology make this clear. Richard Davidson and co-workers have shown that relatively positive, up, approach-seeking people are more likely to be left-brain activated (as measured by EEG) and show stronger immune responses to a novel challenge (flu vaccine) than are avoidance, negative emotion (depression, anxiety) right-brained people.  At the same time, James Pennebaker and colleagues have shown that the very act of repressing information from consciousness lowers immune function while sharing information with others (or even a diary) has the opposite effect. Why should the immune system be so important and why should it react in this way?

A key variable in my mind is that the immune system is an extremely expensive one—we produce a grapefruit-sized set of tissue every two weeks—and we can thus borrow against it, apparently in part for brain function. But this immediately raises the larger question of how much we can borrow against any given system—yes fat for energy, bone and teeth when necessary (as for a child in utero), muscle when not used and so on—but with what effects? Why immune function and repression?

While genetics is, in principle, important to all of biology, I thought it would be irrelevant to the study of self-deception until way into the distant future. Yet the 1980s produced the striking discovery that the maternal half of our genome could act against the paternal, and vice-versa, discoveries beautifully exploited in the 90’s and 00’s by David Haig to produce a range of expected (and demonstrated) internal conflicts which must inevitably interact with self-deception directed toward others. Put differently, internal genetic conflict leads to a quite novel possibility: selves-deception, equally powerful maternal and paternal halves selected to deceive each other (with unknown effects on deception of others).

And consider one of the great mysteries of mental biology. The human brain consumes about 20% of resting metabolic rate come rain or shine, whether depressed or happy, asleep or awake. Why? And why is the brain so quick to die when deprived of this energy? What is the cellular basis for all of this? How exactly does borrowing from other systems, such as immune, interact with this basic metabolic cost? Biologists have been very slow to see the larger picture and to see that fundamental discoveries within psychobiology require a deeper understanding of many fundamental biological processes, especially the logic of energy borrowed from various sources.

Finally, let me express a surprise about psychology. It has led the way in most of the areas mentioned, e.g. immune effects, neurophysiology, brain metabolism. Also, while classical depth psychology (Freud and sundries) can safely be thrown overboard almost in its entirety, social psychology has produced some very clever and hopeful methods, as well as a body of secure results on biased human mentation, from perception, to organization of data, to analysis, to further propagation. Daniel Gilbert gives a well-appreciated lecture in which he likens the human mind to a bad scientist, everything from biased exposure to data and biased analysis of information to outright forgery. Hidden here is a deeper point. Science progresses precisely because it has a series of anti-deceit-and-self-deception devices built into it, from full description of experiments permitting exact replication, to explicit statement of theory permitting precise counter-arguments, to the preference for exploring alternative working hypothesis, to a statistical apparatus able to weed out the effects of chance, and so on.