People may form inaccurate impressions about us from our social media posts, finds new Cornell University research that is the first to examine perceptions (认知) of our personalities based on online posts.

An analysis of online status updates found great difference between how viewers saw the authors across a range of personality traits, and the authors’ self-perceptions.

Viewers rated the Internet users on average as having lower self-esteem and being more self-revealing, for example, than the users rated themselves, Status updates containing photos, videos or links in addition to text facilitated more accurate assessments than those with just text the researchers found.

Overall, they said, the study sheds light on the dynamic process by which a cyber audience tries to make sense of who we are from isolated fragments (碎片) of shared information, jointly constructing our digital identity.

“The impression people form about us on social media based on what we post can differ from the way we view ourselves.” said Qi Wang, professor of psychology and director of the Culture &. Cognition Lab. “A mismatch between who we are and how people perceive us could influence our ability to feel connected online and the benefits of engaging in social media interaction.”

The Cornell researchers believe their study is the first to investigate audience perceptions of social media users through their posts, On platforms, users often share fragmentary personal narratives while interacting with “friends” they may know only a little or sometimes not at all.

Interestingly, the study found that online status updates generated perceptions of users that were consistent with cultural standards in offline contexts concerning gender and ethnicity—even though viewers were blind to their identities.

Wang said the findings could help developers design interfaces that allow people to express themselves most authentically.

“If people’s view of us is very different from who we actually are, or how we would like to be perceived.” Wang said, “it could harm our social life and well-being.”

While we might like to think we would rush to someone’s assistance, we know from studies that often people hang back and this can have tragic consequences.

One of the most famous examples of this is the tragic case of Kitty Genovese who was fatally stabbed (刺伤) in Kew Gardens, New York, in 1964. Subsequent investigations concluded that several people saw or heard what was happening, but did nothing to intervene. This has been termed the “bystander effect” — a well-known psychological phenomenon where individuals are less likely to offer help to someone when other people are present. The more people there are, the less likely they are to help.

There are various factors contributing to this effect — people think that others will get involved or intervene. Afterwards people often say they did not feel qualified or senior or important enough to be the one to intervene. It is also partly down to “pluralistic (多元化的) ignorance” — since everyone is not reacting to the emergency, they don’t need to either; it’s not serious because no one else is doing anything. After a serious incident where people have been affected by the bystander effect, they are often horrified that they didn’t do anything—they can’t believe they had not realized it was more serious or that they didn’t think to get involved.

The important thing to understand though is that other studies have shown that once people are aware of the bystander effect, they are less likely to be affected by it. Self-awareness is the best approach to it. When confronted with an emergency, think to yourself how you would behave if you were on your own. Ignore everyone else and how they are behaving and go with your courage — if you’d call an ambulance, do it. If you’d run for help, do it. If that’s how you would have behaved when you were on your own, then that’s probably the right course of action.

One of the most dangerous insects you need to watch out for during summer is mosquitoes. But no matter how you try to avoid them, some people naturally attract mosquitoes more than others.

One of the most important facts to remember is that mosquitoes track people down by smell and body odour(气味), according to Bart Knols, PhD, a biologist devoted to the study of mosquitoes. The carbon dioxide people breathe out, along with chemicals from the skin, creates an “odour plume” that mosquitoes can detect from up to almost 100 feet away. “Each person gives off more than 300 chemicals from the skin, more than 100 in breathing out,” Knols says.

The specific mixtures on the skin that mosquitoes respond to vary by species. The yellow fever mosquito and Asian tiger mosquito, for example, respond well to lactic acid from skin. African malaria mosquitoes respond to a mix of fatty acids, according to Knols. Your individual mixtures and smells determine how much of a mosquito attraction you are, depending on the mosquito species. The mix of chemicals you produce are only partly in your control. These chemicals depend on your genetic make-up, health condition, diet, skin pH, and so on. “Bacteria(细菌)on the skin break down the mixtures that we give off through our pores(毛孔), and these are the attractive smells,” Knols says. “So it is not actually we that attract mosquitoes, but the bacteria on our skin.”

Although this is a complex and partly understood phenomenon, Knols says that we do all have a unique smell. There are many folk stories about why some people are more or less attractive to mosquitoes. Some people falsely think the blood type is the cause, and others believe taking vitamin B or eating garlic makes people less attractive to mosquitoes—but Knols notes there’s no scientific data backing these claims.