Uncommon Knowledge: Do you want fries with that?

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Do you want fries with that?

The introduction of the potato from the New World to the Old World was responsible, economists have found, for over a quarter of the increase in population and urbanization in the Old World from 1700 to 1900. In a follow-up study, the economists assembled “a dataset that records the date and location of each conflict in Europe, North Africa, and the Near East from 1400 to 2000.” They found that “the increase in agricultural productivity brought about by the introduction of potatoes dramatically reduced conflict,” especially within countries, as land became less worth fighting over.

Iyigun, M. et al., “The Long-run Effects of Agricultural Productivity on Conflict, 1400-1900,” National Bureau of Economic Research (November 2017).

Reading between the lines

By analyzing randomly selected lines from award-nominated movies from the past couple of decades, researchers found that dialogue in movies that won awards — particularly the Best Picture, Best Original Screenplay, or Best Director Oscars — was less complex than dialogue in movies that didn’t win. A much smaller difference was found for the Best Cinematography Oscar, as might be expected for a visual award.

McCullough, H. & Conway, L., “‘And the Oscar Goes to . . .’: Integrative Complexity’s Predictive Power in the Film Industry,” Psychology of Aesthetics, Creativity, and the Arts (forthcoming).

Stay within the lines

Psychologists at Yale found that people who had a more negative opinion of deviant geometric patterns also had a more negative opinion of deviant people — including norm-breakers; minorities; strange-looking people; and exceptionally smart, stupid, rich, poor, fat, or skinny people. This was true not just for Americans but also for people in China, and appeared to manifest in late, but not early, childhood.

Gollwitzer, A. et al., “Relating Pattern Deviancy Aversion to Stigma and Prejudice,” Nature Human Behavior (December 2017).

Conservation blues

A survey of American workers found that perceived scarcity of environmental resources was associated with putting in less effort at work, but only for physically demanding jobs, even controlling for other factors. To test this experimentally, subjects at a French business school were randomly assigned to read a news article that either did or did not highlight a resource shortage. Subjects who read about scarcity performed worse on a subsequent task requiring physical exertion, but not on one that didn’t. The researchers theorize that people are unconsciously trying to conserve energy in response to perceived scarcity, and that promoting sustainable behavior by highlighting scarcity may undermine physical productivity.

Pitesa, M. & Thau, S., “Resource Scarcity, Effort, and Performance in Physically Demanding Jobs: An Evolutionary Explanation,” Journal of Applied Psychology (forthcoming).

God-fearing partisan parents


A political scientist at the University of Pennsylvania analyzed data from a sample of young adults who were surveyed several times between 1965 and 1997. Even though there was no gap in church attendance between Democrats and Republicans in the early 1970s, a significant gap had emerged among this generation by the early 1980s, even controlling for various demographic and background characteristics and views on issues of the day (e.g., Vietnam, women’s rights). While partisan affiliation predicted change in church attendance, church attendance did not predict change in partisan affiliation. Analysis of survey data from the early 2000s also found that the partisan church-attendance gap ballooned in the run-up to the (religiously charged) 2004 election, but only for parents with children at home.

Margolis, M., “How Politics Affects Religion: Partisanship, Socialization, and Religiosity in America,” Journal of Politics (forthcoming).

Kevin Lewis is an Ideas columnist. He can be reached at