Since the 1950s, psychology has expanded rapidly with the number
of research articles published per year doubling between 1960 and 1990
and tripling between 1990 and 2010.
In addition to the growth in cognitive psychology, which emphasized individual mental abilities
advances in social psychology have demonstrated the power of the social environment.
Experiments by social psychologists Kurt Lewin, Solomon Asch, and Stanley Milgram
provided a clearer picture of the way that the behavior of other people influences our thinking and our actions.
The development of new methods of recording the activity of the nervous system and visualizing the brain
have helped neuroscience emerge as a central concern of psychology, influencing all areas of study.
Cognitive neuroscience is an interdisciplinary effort to link brain activity to cognitive processes
such as perception, thinking, and memory.
Experiments by Roger Sperry and Michael Gazzaniga described
how the right and left hemispheres of the brain contribute to cognition
based on studying “split-brain” patients whose hemispheres were unable to communicate with each other.
In the 1960s and 70s
scientists observed a variety of ways in which humans and animals are not born as “blank slates” as Aristotle suggested.
Children have an uncanny ability to learn language in a short period of time from a jumble of sounds.
Rats are able to associate nausea with food faster than other stimuli.
Multiple species seem programmed from birth to engage in social behaviors with other members of their species.
These findings represent insights from evolutionary psychology, an approach to understanding behavior and the mind
by trying to understand the adaptive significance of the behavior.
Each of these behaviors has been shaped by natural selection to promote survival.
In a sense, psychology has returned once again to its roots in physiology and evolutionary biology
as discoveries in brain science and behavior genetics have provided new insights on some old puzzles of behavior.