Snake detection theory

The snake detection theory,^[1][2][3] also sometimes called the snake detection hypothesis, suggests that snakes have contributed to the evolution of primates' visual system. According to the theory, predatory pressure from snakes has selected individuals who are better able to recognize them, improving their survival chances and therefore transferring such skill to their offspring. From this point of view, snakes were responsible for the modification and expansion of primate visual systems which made vision the most developed sensory interface with the external environment for modern primates. In her book The Fruit, the Tree, and the Serpent (2009),^[4] anthropologist Lynne Isbell writes that snakes evolved to be difficult to detect and mortally dangerous. Surviving the peril of snakes for millions of years required selective pressure favoring primates' specialized visual systems. Compared to that of other mammals, the pulvinar region of the brain – which helps to visually detect relevant objects – is disproportionately large and effective in the brains of primates (including humans).

The concept of snakes being a special threat to humans has been confirmed by population-based studies. Ophidiophobia (phobia of snakes) is one of the most common and intense phobias among the general population. Furthermore, a study reported that around 50% of people experience dreams about snakes.^{[5][dead link]}