According to Peterson, people have four types of psychological systems which either attract them toward pleasurable sensations or repel them from harmful ones.

"Drugs that people like to abuse either activate the positive systems or deactivate the negative ones," he says. "Most drugs that people really like are tied to the pleasant system."

Peterson says this propensity to take mind-altering drugs is based on a natural tendency to explore it," Peterson says. "It's the price we pay for intense curiosity."

Peterson cites the example of a child who spins around and around in circles until passing out. The spinning is motivated by the child's desire to explore the unknown, he says.

Book on the 'Net

Peterson's latest project, however, harkens back to his earlier interest in the psychology of the Cold War. Peterson has just finished a book he has worked on for 10 years about the motivation for social conflict.

"It describes what I think myth means and what I think about how our brains work," Peterson says.

He compares belief systems to religions and says the Cold War can basically be interpreted as a fight between two different religious views.

"I'm interested in what motivates individuals to participate in atrocious acts to support their ideological identification," Peterson says.

He cites one such atrocity as the use of mass rape as an instrument of social policy in the former Yugoslavia.

Peterson has released the book on the Internet to get some feedback from outside readers prior to publication. A program on his computer allows check who has looked at the manuscript. The book may be reached on the World Wide Web at the following site: http://wjh-www.harvard.edu/~jbp/godsofwar.html.

Showcasing the book electronically may reflect what students call his "young" style. "He just seems to be much more knowledgeable and on the cutting edge of where psychology is going," Kendrick says.

In his spare time, Peterson says he enjoys surfing on the Internate and playing the piano, but he says his two small children, ages one and three, keep him active enough.