The world may be deeply divided, but there are some things we all just know to be true, even if we disagree on the reasons. For example, people are becoming less likely to help a stranger in need, not like in the old days when we looked after each other. Different people might have different explanations for the phenomenon, but we can all agree it's real, right?

One of science's most important tasks is to challenge these accepted truths, and now a new paper draws on 511 studies over 61 years to show helpfulness to strangers is actually increasing, at least in the USA. It took scientists from China and the Netherlands to reveal this bit of good news about America to Americans, although the studies they analyzed were done at US institutions.

Many measures of trust and social connection really do tell a grim story of decline, particularly in the United States, so it's easy to assume the pattern is universal. However, for decades psychologists have been investigating how much people help each other, so assumption isn't necessary. A meta-analysis of research on the topic from 1956-2017 published in Psychological Bulletin finds a slow but steady positive trend.

The studies were of two sorts: public goods dilemmas (PGDs) and prisoners' dilemma (PD) games. In PGDs, players are given money and decide how much to keep and how much to share with other players, with shared contributions multiplied by a factor. In PD games, players can earn a reward from cooperating but do better still if they rat out a cooperating partner.

The basic concepts have been tested in slightly varying formats for decades, and while differences in design have an impact, over the period of the current study, cooperation increased by almost 20 percent.

Even the authors didn't expect this result. 

“We were surprised by our findings that Americans became more cooperative over the last six decades because many people believe U.S. society is becoming less socially connected, less trusting and less committed to the common good,” said Professor Yu Kou of Beijing Normal University in a statement. 

With 63,000 participants in the studies, the sample size is excellent, but with most conducted among university students, it may tell us more about trends among educated young people than the population as a whole.

One possible explanation is that cities, contrary to perceptions, increase cooperation. Small towns may promote cooperation with neighbors, but suspicion of strangers and reluctance to help. Bigger cities force frequent interactions with unfamiliar faces. “It’s possible that people gradually learn to broaden their cooperation with friends and acquaintances to strangers,” said co-author Professor Paul Van Lange of Vrije Universiteit Amsterdam. This, and a trend towards living alone, may have overwhelmed counterbalancing factors. More speculatively, social media may have similar effects.

To say these findings go against expectations is quite an understatement. Assisting strangers is considered a key marker of social connectedness. The paper notes Robert Putnam's book Bowling Alone, which describes declining social connectedness and has been cited more than 95,000 times, according to Google Scholar. No doubt many of these citations were referencing the compelling evidence Putman presents as to why such connectedness matters, but perhaps most took on faith his pessimistic take on its direction.

Helping strangers is obviously beneficial to those needing help away from support networks, but social scientists also consider it both a marker and facilitator of many other things. 

“Greater cooperation within and between societies may help us tackle global challenges, such as responses to pandemics, climate change and immigrant crises,” Kou said. 

Moreover, the paper notes: “Variation in trust and cooperation among strangers is positively associated with variations in government effectiveness, market competitiveness and economic growth.”