What happens when we think that others expect us to fail? My research shows that these “underdog expectations” can actually motivate (激励) people to try to prove others wrong, especially those they find less trustworthy, — leading them to perform better.

I conducted an experiment asking volunteers to do a computer task that included clicking on rapidly moving circles. They were told that someone was observing their performance on the task. They would receive one of three messages — stating underdog expectations, high expectations, or neutral (中立的) expectations — from the observer. Volunteers then performed the task. I found that those who experienced underdog expectations performed the best.

There are countless stories about underdogs being successful. For example, Aly Raisman, a three-time Olympic gold medalist in gymnastics, specially mentioned this motivation after reporters suggested she was too old to succeed at the last Olympics, “It’s obviously not something that people expected or that’s easy to do after you’re taking a year off or being the ‘Grandma’ or whatever they like to say. So, I’m happy I proved everyone wrong.”

Of course, there are also many more examples of people failing to overcome the low expectations others set for them. So when does being an underdog lead to success rather than failure?

I ran a second study. Before volunteers received any expectations, they were casually given information about the observer’s trust. Results show that the desire to prove others wrong only turned into better performance in the face of less trustworthy observers, while it backfired when it came from more trustworthy observers. Trying to prove highly trustworthy people wrong appears to have caused a sense of anxiety, which weakened the following performance. In contrast, people experiencing underdog expectations from less trustworthy observers were able to use the desire to prove others wrong and perform successfully.

My work suggests that more people can achieve success when they think that others view them as underdogs — if they view others as less trustworthy and direct their motivation to prove them wrong toward performing better.

Mythology(神话) is rich with tales of dragons and the magical characteristics of their blood. It was supposed to be capable of curing certain diseases and was widely sought after.

A new study at George Mason University in Virginia suggests that the blood of the Komodo dragon, the largest living lizard on the planet, is loaded with chemicals that could be used as antibiotics(抗生素).

Komodo dragons, which are native to parts of Indonesia, attack large animals like water buffalo and deer with a bite to the throat. If their prey (猎物) does not fall immediately, the dragons rarely continue the fight. Instead, they back away and let the mix of mild poison and dozens of disease-causing bacteria found in their saliva(唾液) finish the job. They track their prey until it falls, victim to the poison and the bacteria, and then they can feast without a struggle. The strange thing is Komodo dragons are not affected by the bites of other dragons.

This fact interested the researchers who then examined the blood of Komodo dragons and discovered that it possessed qualities that are likely to have important medicinal uses. They recognized 48 elements that had previously been unknown to science and decided to test them in their laboratory. They exposed two types of disease-causing bacteria to eight of the most promising elements found in dragon blood. They found that the growth of both bacteria were strongly affected by seven of the dragon blood elements.

These results are important because antibiotic-proof bacteria are an increasing problem in hospitals. Such bacteria are thought to cause 700,000 deaths in hospitals each year around the world. It could be that the work of scientists with Komodo dragon blood could solve this increasingly common problem and their work may prove that dragon’s blood is just as magical as myths suggest.

How sharks navigate the vast and seemingly featureless ocean has long been a mystery. Now there's evidence they may follow their noses. Sharks rely on their sense of smell to help chart a path through the ever-shifting waters of the deep seas, according to a new study. Scientists have supposed that the animals navigate by monitoring smell clues or the Earth's magnetic field, but no one knew for sure.

In new experiments near San Diego, scientists ferried wild leopard sharks about 6 miles(10 kilometers)away from their preferred habitats, fitted them with tracking devices, and stuffed some of the animals' noses with cotton balls. Just 30 minutes after being released facing the wrong way, sharks with full use of their smells made a corrective U-turn and then headed straight back to shore, "says study leader Andrew Nosal, a researcher at the Scripps Institution of Oceanography, California. Sharks with stuffed noses, meanwhile, "appeared lost, "wandering aimlessly and

swimming more slowly than those that could smell freely.

To test sharks' sense of direction, Nosal and colleagues captured several dozen leopard sharks, a small species found along the coast from Washington State to northern Mexico.

After blocking some of the animals' noses, the scientists then took the animals on a cruise to deeper waters before slipping them, safe and unharmed, back into the sea. Even the sharks with plugged noses made it partway back to shore before their tracking devices fell off. But those with unplugged noses "took very straight paths" toward home. Nosal supposes the sharks likely sniffed out chemical molecules found in higher and higher doses nearer to land.

Other scientists, however, remain unconvinced. Maybe the animals with plugged noses "were confused by the fact that they had something stuffed in their nose," says Kim Holland, a marine biologist at the University of Hawaii at Manoa. It's also unlikely the animals were following a smell that grew stronger closer to land, adds Jayne Gardiner, a sensory biologist at the New College of Florida. Animals that couldn't smell a thing still turned toward the beach, which "suggests something else is really guiding them," she says.

Study leader Nosal responds that sharks with cotton-stuffed nose willingly eat, suggesting that a congested nose doesn't upset them much. He agrees that sharks use a variety of markers to find their way, "but the point is that smell participates in navigation, "he says. "Our study was only the first step in solving this mystery. "