People who multitask all the time may be the worst at doing two things at once, a new research suggests. The findings, based on performances and self-evaluation by about 275 college students, indicate that many people multitask not out of a desire to increase productivity, but because they are easily distracted and can’t focus on one activity. And “those people turn out to be the worst at handling different things,” said David Sanbonmatsu, a psychologist at the University of Utah.

Sanbonmatsu and his colleagues gave the students a set of tests and asked them to report how often they multitasked, how good they thought they were at it, and how sensation-seeking (寻求刺激) or imperative (冲动) they were. They then evaluated the participants’ multitasking ability with a tricky mental task that required the students to do simple mathematical calculations while remembering a set of letters.

Not surprisingly, the scientists said, most people thought they were better than average at multitasking, and those who thought they were better at it were more likely to report using a cellphone while driving or viewing multiple kinds of media at once. But those who frequently deal with many things at the same time were found to perform the worst at the actual multitasking test. They also were more likely to admit to sensation-seeking and impulsive behavior, which connects with how easily people get bored and distracted.

“People multitask not because it’s going to lead to greater productivity, but because they’re distractible, and they get sucked into things that are not as important.” Sanbonmatsu said.

Adam Gazzaley, a researcher at the University of California, San Francisco, who was not a member of the research group, said one limitation of the study was that it couldn’t find out whether people who start out less focused tend toward multitasking or whether people’s recognizing and understanding abilities change as a result of multitasking.

The findings do suggest, however, why the sensation-seeker who multitask the most may enjoy risky distracted driving. “People who are multitasking are generally less sensitive to risky situations.” said Paul Atchley, another researcher not in the group. “This may partly explain why people go in for these situations even though they’re dangerous.”

Ants live in complex colonies (群落), sometimes called nests. They need to defend their colony, seek food and take care of little ones. Successfully performing all these complex tasks requires reliable communication among nestmates. Recent work shows how their societies depend on the exchange of reliable information.

Human communication depends mainly on the sound of their voice, their appearance or their clothes. Ants, however, rely primarily on their sharp sense of smell.

An outer shell covers an ant’s body, which carries a unique smell that varies from individual to individual and gives each ant a unique smell feature that other ants can recognize. This smell feature can communicate important information.

For ants and other insects, receiving chemical information begins when a smell enters the small hairs located along their antennae (触角). These hairs contain special receptors, called chemosensory neurons (感化性神经元), which sort and send the chemical information to the ant’s brain. Smells, such as those given off from an ant’s oily coat, act like chemical “keys”. Ants can smell these “keys” only if they’re placed into the correct set of chemosensory neuron “locks”. A neuronal lock remains shut to any smells except its particular key. The ant’s brain can obtain this sensory information to make decisions that lead to cooperation between nestmates or battles between non-nestmates.

To better understand how ants recognize and communicate information, researchers used laboratory tools to affect their sense of smell. They were interested in what happens when an ant’s sense of smell goes wrong.

When they messed with ants’ sense of smell — shutting down or flooding their smell receptors — they found that ants exercised self-control and chose to accept rather than attack their fellow ants. When the ants lost their sense of smell, and their ability to recognize accurate information became weak, they no longer stuck together in a united colony.

The researchers discovered that if the means of communication is interrupted, it spells doom for their colony. Ant societies break down and the colony quickly dies.

If you were like most children, you probably got upset when your mother called you by a sibling’s (兄弟姐妹的) name. How could she not know you? Did it mean she loved you less?

Probably not. According to the first research to tackle this topic head-on, misnaming the most familiar people in our life is a common cognitive (认知的) error that has to do with how our memories classify and store familiar names.

The study, published online in April in the journal Memory and Cognition, found that the “wrong” name is not random but is always fished out from the same relationship pond: children, siblings, friends. The study did not examine the possibility of deep psychological significance to the mistake, says psychologist David Rubin, “but it does tell us who’s in and who’s out of the group”.

The study also found that within that group, misnaming occurred where the names shared initial or internal sounds, like Jimmy and Joanie or John and Bob. Physical resemblance between people was not a factor. Nor was gender.

The researchers conducted five separate surveys of more than 1,700 people. Some of the surveys included only college students, others were done with a mixed-age population. Some asked subjects about incidents where someone close to them—family or friend—had called them by another person’s name. The other surveys asked about times when subjects had themselves called someone close to them by the wrong name. All the surveys found that people mixed up names within relationship groups such as grandchildren, friends and siblings but hardly ever crossed these boundaries.

In general, the study found that undergraduates were almost as likely as old people to make this mistake and men as likely as women. Older people and women made the mistake slightly more often, but that may be because grandparents have more grandchildren to mix up than parents have children. Also, mothers may call on their children more often than fathers, given traditional gender norms (常态). There was no evidence that errors occurred more when the misnamer was frustrated, tired or angry.