If asked, most researchers would probably say they had one (or a few) favorite project(s) among the research studies they had conducted over their careers. Some projects may stand out in one's mind as being more fun to work on than were others, or it may be the reaction of the field to a published product that stands out.

My personal list of favorite projects would have to include the heat-aggression in baseball study I conducted with Rick Larrick and Steve Fein. The official scientific reference for this study is:

Reifman, A. S., Larrick, R. P., & Fein, S. (1991). Temper and temperature on the diamond: The heat-aggression relationship in major league baseball. Personality and Social Psychology Bulletin, 17, 580-585.

I do not teach social psychology (even though my Ph.D. is in social psych, my faculty appointment is in human development and family studies at Texas Tech University). Still, I am fortunate enough to be able to give an annual lecture on the heat-aggression in baseball study to the undergraduate social psych class of my TTU colleague Darcy Reich. Last week I gave this guest lecture for the third straight year, each time during Darcy's summer session class (what better time of year to speak about heat and aggression?).

Rick, Steve, and I came up with the idea for such a study during the summer of 1987 (the end of my third year at Michigan and Rick and Steve's first). Based on a landmark Michigan-based article by Dick Nisbett and Tim Wilson (Psychological Review, 1977), I try to be very cautious about claiming an impetus for my thought processes. Having said that, I would say there were three events that led Rick, Steve, and me to conduct the heat-aggression in baseball study:

*It was a very hot summer for us in Ann Arbor.

*An article by Craig Anderson, a prolific heat-aggression researcher, came out in the June 1987 Journal of Personality and Social Psychology on temperature and crime rates.

*Major League Baseball was dealing with a "beanball war" that season, as exemplified by the July 20, 1987 cover of Sports Illustrated. (After you click on the preceding word "cover," be sure to scroll down far enough when the page comes up.)

I remember that Rick, Steve, and I went for pizza one evening at a place on Maynard whose name I can't remember, to discuss our plans for the study. In conducting the study, each of us spent long hours in the UM libraries, going over microfilm rolls of major newspapers to look at randomly selected baseball box scores (for the hit-by-pitch data, our measure of aggression) and corresponding weather pages (to record the high temperature in the home city the day of the game). Nowadays, box scores are readily available on the web, with weather conditions at the game included in the box score.

To make a long story short, we conducted the initial parts of the study in 1987, presented our results as a poster at the 1988 convention of the American Psychological Association, then published our final results in PSPB in 1991, as noted above (we had to do some additional analyses for the journal version). Beyond some initial media coverage of the study in 1988 and my annual guest lecture at Texas Tech, the study has continued to live on in a number of ways:

*Citation by Dean Keith Simonton in a 2003 Annual Review of Psychology chapter on "Qualitative and Quantitative Analyses of Historical Data."

*Citation by Anderson in several articles and chapters (click here for his list of recent publications).

*Citation by Eric Sundstrom, Paul Bell, and colleagues in a 1996 Annual Review of Psychology chapter on "Environmental Psychology 1989-1994."

*Continued citation in several social psychology textbooks.

*Inclusion of the study in several social psych professors' online syllabi and lecture notes (a search at Google, with the keyword set "reifman" "larrick" "fein" -- keeping the quotation marks -- currently yields 35 hits).

*A reprinting of our journal article in the book Psychology is Social.

*Application by Tom Timmerman of our idea that hit-by-pitch instances measure aggression, to a different context, namely the question of whether black batters were more likely to get hit by a pitch than their white counterparts, as part of the climate of prejudice just after the integration of Major League Baseball.

*And last but not least, publication of a letter of mine in the July 27, 1998 issue of ESPN The Magazine, in response to an article in the June 15, 1998 issue on hit batters that omitted our research.

My bottom line is that, if a topic such as baseball that has interest to many people can get students excited about doing research, then that may be the heat-aggression study's main contribution.