James Mark Baldwin (Columbia, South Carolina, 1861—1934) was an American philosopher, educated at Princeton and several German universities.
He was professor of philosophy at the University of Toronto (1889), of psychology at Princeton (1893), and subsequently (1903) of philosophy and psychology in Johns Hopkins University.
Prominent among experimental psychologists, he was one of the founders of the Psychological Review.
In 1892 he was vice-president of the international Congress of Psychology held in London, and in 1897—1898 president of the American Psychological Association; he received a gold medal from the Royal Academy of Arts and Sciences of Denmark (1897), was honorary president of the International Congress of Criminal Anthropology held in Geneva in 1896, and was made an honorary D.Sc. of Oxford University.
Baldwin's most important theoretical legacy is the concept of the Baldwin Effect or Baldwinian evolution. Baldwin proposed, against Lamarck, that there is a mechanism whereby epigenetic factors come to shape the genome as much as - or more than - natural selection pressures. In particular, human behavioural decisions made and sustained across generations as a set of cultural practices ought to be considered among the factors shaping the human genome.
For example, the incest taboo, if powerfully enforced, removes the natural selection pressure against the possession of incest-favoring genes. After a few generations without this natural selection pressure, unless such genetic material were profoundly fixed in the genome, it would tend to diversify and lose its function. Humans would no longer be innately averse to incest, but would rely on their capacity to internalize such rules from cultural practices.
The opposite case can also be true: cultural practice might selectively breed humans to meet the fitness conditions of new environments, cultural and physical, which earlier hominids could not have survived. Baldwinian evolution might strengthen or weaken a genetic trait.
Although relatively obscure in his time, Baldwin's contribution to this field places him at the heart of contemporary controversies in the fields of Evolutionary psychology and wider Sociobiology.
Apart from articles in the Psychological Review, he has written:
Handbook of Psychology (1890), translation of Ribot’s, German Psychology of To-day (1886);
Elements of Psychology (1893);
Social and Ethical Interpretations in Mental Development (1898);
Story of the Mind (1898);
Mental Development in the Child and the Race (1896);
Thought and Things (London and New York, 1906).
He also largely contributed to the Dictionary of Philosophy and Psychology (1901—1905), of which he was editor in-chief.