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Whether playing tricks, mimicking speech, or holding “ funerals ,” crows and ravens (collectively known as corvids) have captured the public’s attention due to their unexpected intelligence. Thanks to results from a new Current Biology study, our understanding of their capabilities only continues to grow, as researchers from the University of Tübingen found for the first time that crows can perform statistical reasoning. These results can help scientists better understand the evolution of intelligence (and may give us a better appreciation of what’s going on in our backyard).

Bird brains

With a population of over 27 million and counting, crows seem almost ubiquitous across the US. Their loud “caws” are hard to miss, and the tone of these cries varies depending on what the birds are communicating. Like other corvids, crows have a large brain for their size and a particularly pronounced forebrain , which is associated with statistical and analytical reasoning in humans. Thanks to these attributes, ornithologists and animal behaviorists have found crows doing various “intelligent” activities, such as using twigs as tools to extract bugs from tree bark. Some experts have even classified corvids as having the same intelligence as a 7-year-old child.

Beyond using tools, corvids can also do basic mathematical functions, like adding or subtracting. “In the scheme of the natural world, very few animals are demonstrated to possess much in the way of mathematical intelligence (beyond basic numerical discrimination)—things like numerical competence, an understanding of arithmetic, abstract thinking, and symbolic representation,” explained Dr. Kaeli Swift, a postdoctoral researcher in bird behavior at the University of Washington (she was not involved in the Current Biology study). “That several corvid species have been demonstrated to possess some of these skills makes them quite special.”

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Anyone who has played a real-time strategy game probably ponders this question when preparing for a fight: Is it better to have a huge number of relatively weak units or a smaller number of extremely powerful ones? But the question predates computer games and virtual war machines. Theoreticians started tackling the problem in response to the real-world carnage of World War I, where it was posed as a question of army size vs. fighting strength.

In the years since, the ideas developed for human warfare have been adapted to apply to non-human combatants, most notably social insects, which can mobilize large forces when engaging in combat. In the early 1990s, researchers who studied ants argued that finding the right balance between force size and capability depended in part on the environment. Complex environments, they theorized, favored smaller numbers of capable units that could occupy key terrain. Simpler environments, by contrast, would allow massive waves of weak units to Zerg rush an outnumbered opponent.

That idea has been difficult to test empirically. But three researchers from the University of Western Australia (Samuel Lymbery, Bruce Webber, and Raphael Didham) have now put it to the test, using a combination of Age of Empires and live ants.

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Political polarization in the US has become a major issue, as Republicans and Democrats increasingly inhabit separate realities on topics as diverse as election results and infectious diseases. An actual separation seems to underly some of these differences, as members of the two parties tend to live in relatively homogeneous communities, cluster together on social media, and rely on completely different news sources.

That's not a recipe for a functional society, and lots of work has gone into exploring the impact of polarization, as well as possible means of reducing it. Now, a team of researchers has tested whether social media can potentially help the situation by getting people with opposite political leanings talking to each other about controversial topics. While this significantly reduced polarization, it appeared to be more effective for Republican participants.

Anonymity is key

The researchers zeroed in on two concepts to design their approach. The first is the idea that simply getting people to communicate across the political divide might reduce the sense that at least some of their opponents aren't as extreme as they're often made out to be. The second is that anonymity would allow people to focus on the content of their discussion, rather than worrying about whether what they were saying could be traced back to them.

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Social insects, which don't have very large nervous systems, are capable of remarkably sophisticated behavior, such as the direction-giving dance by bees or the lifesaving rafts formed by fire ants. In these cases, the benefits of this behavior—more food or survival, respectively—are pretty obvious. But there are also cases where the benefits are less than obvious, so how do insects collectively decide to engage in a risky activity?

Researchers are studying a species of ant, the weaver ant Oecophylla smaragdina , that can move vertically amid trees by building a ladder using its own body. The effort takes a lot of workers away from foraging for as long as the ladder is in place, making it a major investment. But in most cases, the rewards will be uncertain; there's only a payoff if the ants find a significant food source at the newly accessed level.

To make the decision, ants appear to judge the distance between their location and the destination. But not every ant makes the same judgment, and it's possible to trick the ants into building longer ladders by moving the destination.

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There is a reason countless songs about loneliness exist. Many are relatable, since feeling alone is often part of being human. But a particular song or experience that resonates with one lonely person may mean nothing to someone else who feels isolated and misunderstood.

Human beings are social creatures. Those who feel left out often experience loneliness. To investigate what goes on in the brains of lonely people, a team of researchers at UCLA conducted noninvasive brain scans on subjects and found something surprising. The scans revealed that non-lonely individuals were all found to have a similar way of processing the world around them. Lonely people not only interpret things differently from their non-lonely peers, but they even see them differently from each other.

“Our results suggest that lonely people process the world idiosyncratically, which may contribute to the reduced sense of being understood that often accompanies loneliness,” the research team, led by psychologist Elisa Baek of USC Dornsife, said in a study recently published in Psychological Science.

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Many Americans have been shocked by the frequency with which people who claim to love our democracy have supported blatantly undemocratic efforts to limit people's ability to vote or to selectively discard votes already cast. Unfortunately, this sort of democratic backsliding is far from a US-specific problem. Despite widespread support for democracy in countries like Venezuela and Hungary, people have turned out in large numbers to vote for autocrats.

A new study performed in the US suggests at least one explanation for the problem: People across the political spectrum appear to believe their political opponents are likely to take anti-democratic action if given the opportunity. And the strength of this belief correlates with a slightly increased willingness to take those actions first.

Nobody says they like this stuff

The finding, from a University of California, Berkeley-Massachusetts Institute of Technology collaboration, is based on demographically representative survey populations, which were asked about several potential anti-democratic actions. For example, those surveyed were asked if they agreed with reducing the number of voting facilities in towns that support the opposing party. Similar questions got at things like banning rallies, limiting freedom of expression, ignoring court rulings, or resorting to violence. After being asked for their own opinions, people were then asked whether they thought their political opponents supported these anti-democratic approaches.

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Reasoning about probabilities is something humans can't always manage especially well, but it's clearly a skill we're capable of. In the wider world of animals, however, there are very few species we can say are able to make choices based on probabilities. So far, the only animals that have demonstrated the ability to make choices based on statistics are our fellow primates and the kea, an alpine parrot from New Zealand.

All the species where this ability had been seen have a large brain relative to their body size, a feature that is associated with many advanced cognitive capabilities. So it was reasonable to conclude that statistical reasoning required some significant mental horsepower. But a study released on Thursday indicates that managing probabilities may be more widespread than we think since an animal with a relatively small brain—the giraffe—is apparently capable of it.

Chances are...

Reasoning based on probability and statistics sounds complicated, but we do it all the time. We weigh the likelihood of various factors when deciding what to bet in poker or which route to take on a commute. We're not always good about it; if we were, we'd freak out more about driving than we do about air travel. But the capacity to do so is there.

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Our brains are filled with lots of specialized structures that do things like process visual information, handle memories, or interpret language. One of the ways we try to understand what a brain is capable of is by comparing it with the brains of other species—what structures are present in the brain, and what behaviors those brains support.

But what if the animal doesn't have a brain? Presumably, most of the behaviors we've looked at require at least some sort of centralized nervous system. But there are a lot of species, including anemones, corals, and jellyfish, that have a fairly diffuse nerve net and lack anything that's clearly brain-like. But apparently, that's enough to perform associative learning, the sort most often (forgive me) associated with Ivan Pavlov.

Is our cnidarian learning?

Associative learning is pretty much what it sounds like: Through repetition, an animal learns to associate an event with something that's otherwise unrelated to that event. In Pavlov's case, he trained dogs to associate a specific sound with being fed. Once trained, the dogs would start salivating once they heard the noise—even if food wasn't present. A huge range of animals are capable of associative learning, and it's easy to see how it can provide a selective advantage.

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Piecing together why so many people are willing to share misinformation online is a major focus among behavioral scientists. It's easy to think partisanship is driving it all—people will simply share things that make their side look good or their opponents look bad. But the reality is a bit more complicated. Studies have indicated that many people don't seem to carefully evaluate links for accuracy, and that partisanship may be secondary to the rush of getting a lot of likes on social media . Given that, it's not clear what induces users to stop sharing things that a small bit of checking would show to be untrue.

So, a team of researchers tried the obvious: We'll give you money if you stop and evaluate a story's accuracy. The work shows that small payments and even minimal rewards boost the accuracy of people's evaluation of stories. Nearly all that effect comes from people recognizing stories that don't favor their political stance as factually accurate. While the cash boosted the accuracy of conservatives more, they were so far behind liberals in judging accuracy that the gap remains substantial.

Money for accuracy

The basic outline of the new experiments is pretty simple: get a bunch of people, ask them about their political leanings, and then show them a bunch of headlines as they would appear on a social media site such as Facebook. The headlines were rated based on their accuracy (i.e., whether they were true or misinformation) and whether they would be more favorable to liberals or conservatives.