the development of mental modules that focus on agents in the environment
(Barton, 2000; Boyer & Barrett, 2005). In our ancestors’ environment,
mistaking a rock for a lion had little consequence (as long as one was able
to correct the mistake), but an error in the opposite direction had the
consequence that one’s genes were not passed on to posterity. It has been
suggested that the human mind includes a“hypersensitive agent-detection
device,”abbreviated as HADD (Barrett, 2000). The term“device”means that
HADD is a specialized cognitive module (see section 1.2). Note that this does
not necessarily imply any anatomical localization in the brain. The HADD is
thought of as one of the“inference systems”(a term borrowed from com-
puter science) that interpret environmental stimuli quickly and automatic-
ally(Boyer&Barrett,2016).Suchrapid and automatic response to vital
information is an important adaptation in the evolution of the mind. The
inference system that detects agents is“hypersensitive”in the sense that
there is a human tendency to attribute innocent environmental stimuli to
agents. For example, when hearing a noise in the dark, we often assume
that an animal or a human being has made it until we are convinced that it
has some other cause. The human biasto over-detect agents in the envir-
onment probably contributed to the development of concepts of gods and
spirits (Guthrie, 1993; Barrett & Keil, 1996; Burkert, 1996; Barrett, 2000;
Pyysiäinen, 2009). Notice, however, that recognizing predators and prey
animalsisamatterofsurvivalformanyspeciesandthushardlyformsa
specific human adaptation.
2.2.2 Theory of MindThe humanTheory of Mindenables us to reason about the thoughts and
feelings of others. We will deal with this cognitive ability in more detail in
section 8.1. Gods and spirits have thoughts and feelings, which has far-
reaching consequences for how we interact with them. We do not simply
run away from spirits or kill them with spears (as our ancestors we would have
responded to the presence of dangerous animals) but try tofind out what they
think and how they feel and deal with them accordingly (Boyer, 2001;
Pyysiäinen, 2003). This cognitive capacity is also used for interpreting the
gods’and spirits’goals, intentions, and actions. Psychologist Jesse Bering
(2002) found that whereas people expect the biological functions of dead
friends and relatives to stop after death they keep attributing thoughts and
feelings to them. The Theory of Mind thus seems to be hyperactive in humans,
much the same way as agent-detection. Dead people who have psychological
functions but no biological existence can be thought of as ghosts and spirits
(see also section 1.3).
Evolution 33