Too often, science news extrapolates wildly from the science in question. Take, for example, that time a small study done in mice mutated into diet advice for humans. Press releases are sometimes the origin of the hype; other times, the hype might be added by reporters and editors for some extra juice in the story.

But sometimes, the extrapolation is embedded in the science itself. Researchers are not immune to bias, and sometimes they make unsupported claims based on their data. A paper in PNAS this week takes a big leap from its evidence to claim that the emotion of pride “evolved to guide behavior to elicit valuation and respect from others.” The paper itself has some nifty findings, but getting from the data to the conclusions requires the mental equivalent of an Olympic long jump.

You think humor is just as important as the next guy

What the researchers found—and this is the neat part—is that we think highly of other people who have traits that we ourselves would be proud of. More than 1,300 people from 16 different countries answered a survey about traits like sense of humor, generosity, athletic skill, popularity, and responsibility.

The participants were split into two groups. Half of them answered the survey as if they were the people who had the characteristics in question. They rated how much pride they would feel if things like “People love your sense of humor” were true about them. The other half rated how positively they would view another person with that same trait, such as “People love his sense of humor.”

The ratings were on a scale from one to seven, and the results from the two groups matched closely. For instance, in Belgium, participants rated the pride they would feel for the statement “You are trustworthy” as 6.33 out of 7 (on average). The other group rated a trustworthy person as 6.04 out of 7. Physical attractiveness, on the other hand, was rated 4.77 and 5.41, respectively.

This was the case across all the countries. Correlations are measured using a statistic called Pearson’s r, and, for a perfect correlation (in which one value increases as another increases, without exception and by a perfectly consistent amount), r equals 1. For no correlation whatsoever, r equals 0. The values for all countries in this study were on the high end—from the mid-0.70s upwards. The authors report statistical significance for all of them.

This is intriguing because people aren’t always good at matching internal perceptions with external reality. For instance, we’re not always good at figuring out what we do and don’t know, and people also don’t seem to be great at judging who is actually their friend. The fact that the results were so consistent across countries is an important strength, because it means that the conclusion doesn’t come from just one population.

But not all of the experiments were compelling. The authors also looked at feelings beyond pride, but these often made little sense. For example, it’s not clear why we’d expect someone to be amused that they’re considered trustworthy. Yet the analysis of these results kicked up oddly significant findings—for instance, value and amusement correlated in India. Still, these oddities don’t necessarily detract from the stronger findings of the other work in the paper.

Does this mean pride is evolutionarily adaptive?

There’s also the question of the cross-cultural sample. The countries on the list included the US, Canada, Australia, and six countries from Europe, meaning nine of the 16 countries have shared cultural heritages. Of the remaining seven countries, three—India, Singapore, and the Philippines—were all colonized by European countries, introducing a level of cultural contact that definitely complicates any correlations on cultural variables.

The geographical proximity to Europe of Turkey and Israel also raises the prospect of some shared culture. This really just leaves South Korea and Japan in the clear. Cross-cultural research is difficult and expensive, so it’s not a failing of the research to have a limited selection of countries. But it does mean that the interpretation of the results deserves a bit of caution.

The real leap the authors make, however, is to use their findings to make an evolutionary claim. The researchers’ argument is that humans are a heavily social species that relies on the good opinions of others, especially when resources are scarce. So we try to do things that will make other people think well of us. But if we don’t know how much people will value a given feat (like winning a marathon), we run the risk of wasting our energy on activities that will make us feel pride but won’t actually encourage people to value us.

The authors take their strong correlations as evidence that the emotion of pride evolved in order to steer us toward the right kinds of high-valued behavior. If things we feel proud about are respected by others, then pride can act as a guidance for our behavior.

To be clear, this is a plausible suggestion. If we see something related to social standing appearing in humans all around the globe, hypothesizing that it’s the product of evolution is reasonable. To be more certain, though, we’d need evidence of the only thing natural selection cares about: reproductive fitness, or how many children you have. If we were to find, say, that people whose feelings of pride closely match the values of their communities and that those people have more children, that would be evidence that feeling the appropriate levels of pride is evolutionarily adaptive.

Even then, how much is pride an evolved emotion that is separate from other abilities and feelings? Was the emotion of pride the result of evolution, or was a general ability to calibrate our actions according to the feedback we get from others the result of evolution? These are answerable questions, but they'd need a lot of research from a wider spread of countries (and a lot of research funding). Right now, the evolutionary claim is speculation—interesting speculation, but a solid wander away from the actual data.

PNAS, 2016. DOI: 10.1073/pnas.1614389114 (About DOIs).