11 things you didn’t know were contagious

Germs aren’t the only things you have to worry about “catching.”

Diners are happier when they order entrées that are similar nutritionally to those of their companions, found University of Illinois research. If you’re watching your waistline, place your order first so you’re not tempted by your pals’ cravings.

University students who were randomly paired with roommates highly prone to brooding were likely to “catch” their negative-thinking style after only three months, found a University of Notre Dame study. Recognise that other people may influence how you respond to life’s challenges.

Here are 8 ways to choose optimism.

On the other hand, positive feelings also rub off, according to a seminal study of almost 5,000 people by researchers at Harvard and the University of California, San Diego. When you feel happy, a friend who lives within one mile is 25 percent more likely to feel happy, and neighbours are 34 percent more likely to feel happy. The same data found that an extra $5,000 increased happiness by about 2 percent, a much lower impact than what’s gained by having a joyful friend of a friend (a second-degree connection), which can boost your own good feelings by 10 percent.

Here are 40+ more secrets to a happier life. 

The same research team found that when one person quit smoking, close friends and family members became 36 percent less likely to smoke. The ripple effect: Even very casual acquaintances of the initial quitter became 20 percent less likely to light up.

Here are 15 mind-blowing ways your body heals itself after quitting smoking. 

The brain is hardwired to detect stress in other people, such as increases in breathing rate. This triggers a cascade of our own stress hormones, Heidi Hanna, executive coach and author of Stressaholic, told us. And you don’t need to be in the same room to catch someone else’s stress, which is transmittable via email, texts and social media. (Curt responses could signal someone is under a tight deadline, for example.) When you feel stressed, take breaks and get enough sleep – that’s not selfish. It benefits everyone around you.

Here are 36 ways to make managing stress much easier. 

If you’ve seen someone else scratch an itch and suddenly felt your own skin tingle, you aren’t alone. A study in the journal Science found that mice started scratching themselves when they looked at chronically itchy rodents. In fact, the normal mice near their extra-itchy counterparts ended up scratching twice as often as usual.

Here are 9 things you need to know about eczema (especially if you have it!).

It’s no coincidence you suddenly want a new car after your friend’s visit to the dealership. A 2012 study in the Journal of Neuroscience found that participants rated objects as more valuable when they thought someone else wanted them. “I call this wedding-band syndrome,” psychologist Elizabeth Lombardo, PhD, tells Prevention. “A man is more attractive if someone already wants him – he must be worth having.” Shut the green-eyed monster down by reminding yourself of how thankful you are for what you already own.

A study in the journal Obesity found that when volunteers started a weight-loss program, their partners dropped kilos at about the same rate as them. Use the ripple effect to your advantage by enlisting your partner to join you on your weight-loss journey.

Check out these 36 fast, easy ways to lose weight. 

You’d think distance would keep lonely people from spreading their isolation, but the opposite is true, according to a study in the Journal of Personality and Social Psychology. The findings suggested that after someone started feeling lonely, others in that person’s social group would get lonelier over time, too. The feeling acted like a contagion, rather than a result of lonely people being attracted to other lonely people. The researchers believe groups tend to blow off lonely people, which keeps the cycle going. Nip the cycle in the bud by getting in touch with friends you haven’t heard from in a while.