ABSTRACT
The year 2009 marked both the bicentenary of Charles Darwin’s birth and his book On the Origin of Species (Darwin [1859] 2003). One of Darwin’s points was that living species evolved throughout the passing of time, and that this evolution reflected a propensity for survival that demanded adaptation to environmental stimuli and pressure. In his view, natural species evolve over time through a process of elimination that favors the bestadapted specimen, and this is precisely what shapes their evolution. Darwin built his theory from his observations, which took place over a period of several decades and derived from many geographical locations. He did not, however, approach the question of the evolution of mental constructs. It was too early, and there was still much work to be done with his general theory of the interrelatedness of different species, climate, and the environment. He did, though, write an opus on the expression of the emotions in man and animals (Darwin and Ekman 1998) to illustrate that there is no difference of kind, but only of degree, between man and other animals.
