described above). So one could now combine the psychological find-
ings with their evolutionary background, a combination that is now
generally known as evolutionary psychology. The main point was that we
could better understand how human minds are organized if we took
into account what specialized systems in the brain are for, how they
are supported by special routines in the brain, and under what condi-
tions they evolved though natural selection. This required the connec-
tion and combination of evidence from evolutionary biology, genetics,
neurophysiology, psychology and anthropology.^19[118]
TOOL KIT 3:
EVOLUTIONARY PSYCHOLOGYOur evolutionary history has shaped our inference systems as
evolved responses to recurrent problems in ancestral conditions.
So we must (1) reconstitute the particular features of these
problems in such conditions; (2) deduce what specific computa-
tional principles could solve these problems, and therefore pre-
dict some nonobvious design features; (3) examine whether
there is independent experimental or neurophysiological evi-
dence for the corresponding specialized inference system; and
(4) evaluate how the special system described by psychologists
could have evolved from other systems and whether it would
confer reproductive advantage to its bearers.These stringent requirements explain why evolutionary psychology
is still very much in its infancy. We cannot just consider a human
capacity (e.g., the capacity to read and write) and make up a story that
would make it adaptive (written communication is very convenient).
In this case, it happens that literacy does not require a specific system
in the brain. It just recruits systems that served throughout our history
and still serve other purposes (recognition of visual shapes, segmenta-
tion of words into syllables, motor control of the hand and wrist, etc.).
In some domains, it is quite clear that the way our inference sys-
tems work is an outcome of evolution, because our choices have direct
consequences on our survival and reproductive success. For example,
evolutionary psychologists Don Symons and David Buss have put
together a precise account of many aspects of human sexual behavior:
how people choose partners, what they find attractive, as well as howRELIGION EXPLAINED