woman holding her head (Photo: ZenShui; Frederic Cirou; Getty Images )

You feel it when you smell your mom's cookies, or listen to that song you loved in college. As the cliche goes, it's that "warm and fuzzy feeling"--and it turns out it's a real thing. According to a new study in the journal Emotion, nostalgia really does make you feel warmer. (Watch out: Nostalgia can make you a sucker.)

European and Chinese researchers split 64 students into two groups and asked one group to recall memories that made them feel nostalgic. The students were then asked to guess the temperature of the experiment room. It sounds nuts, but the nostalgic students judged the room to be more than 4 degrees warmer, says Tim Wildschut, Ph.D., a psychologist at the University of Southampton in England.

Why? Wildschut credits something called an "as-if" body loop. Basically, pleasant memories engage the pathways in your brain that were active when you were happy and content, and this emotional comfort extends to your physical state, he explains.

But the warm and fuzzy feeling isn't the only cliche that's backed up by research. Here are five more:

1. You Do Learn from Your Mistakes
Before you register a conscious thought, the lower temporal region of your brain sends out a "warning signal" if you're about to repeat a past mistake, finds University of Exeter research. It takes just .1 seconds for the red flag to go up, the researchers write. Past studies have also shown your brain holds on to more information when you make incorrect predictions than correct predictions. That doesn't mean you won't make the same dumb mistake twice--but at least part of your brain is doing its job, the study suggests. (Avoid the Health Mistakes Men Make.)

2. Santa Claus Is Jolly
That is, he would be if he existed in the overweight body we all know and love. A new study of more than 28,000 people published in Molecular Psychiatry found the gene FTO, which has been linked to obesity, also lowers symptoms of depression by 8 percent. While the FTO gene increases production of a protein that promotes fat mass, it also "turns off" other genes associated with depression, the study authors write. Worth repeating: It's the gene, not being overweight, that lowers depressive symptoms.

3. You Do Make Your Own Luck
Unlucky people are generally more anxious and rigid, which disrupts their ability to notice and capitalize on new opportunities, finds research conducted by Richard Wiseman, Ph.D., of the University of Hertfordshire. On the other hand, Wiseman found that most fortunate people actually "make" their own luck by being observant and open to change, by putting faith in their intuition, and by having a resilient, optimistic attitude that helps them convert tough breaks into new opportunities, he writes in his book The Luck Factor. (Learn the 5 Lies You Tell Her Every Day. Avoid these fibs that'll put you in the doghouse.)

4. The Pinocchio Effect Is Real
Your nose knows when you're lying. But unlike the famous wooden boy, it doesn't grow--it heats up. Using thermography, researchers at Spain's University of Granada found the temperature of your nose (and nearby orbital muscles) rises when you fib. Here's why: the insular cortex in your brain, which regulates body temperature and is tied to self-awareness, may also have physiological connections to your schnoz, the research suggests.

5. Love Makes You Sick
When you fall in love, your brain is flooded with a potent cocktail of neurotransmitters including dopamine, adrenaline, and oxytocin. All of these boost your mood and give you that sense of energy and elation you feel when you tumble head-over-heels for a new mate, finds research from Syracuse University. That's good. But the "high" you get from this flood of brain chemicals also makes it difficult to eat, sleep, or concentrate, and can lead to panic attacks, chest pressure, and physical sickness, shows a Rutgers University Study. (Will your first date lead to a second? Take the Men's Health Dating Quiz.)