The preparedness theory of phobia purports that humans have a predisposition to develop fear of specific objects and situations that threatened survival in their evolutionary past (phylogenetic fears). These biological associations augment the widely accepted learning model of fear, suggesting that phylogenetic fears are markedly different from fears developed during the lifetime of an individual (ontogenetic fears). Specifically, four characteristics, proposed by Martin Seligman in 1971, distinguish phobias from fears conditioned in the laboratory: (1) ease of acquisition, (2) irrationality, (3) belongingness, and (4) high resistance to extinction.