As Thanksgiving approaches, Americans will be reflecting on things they're grateful for: family, health and good fortune of various sorts.

It might be wise, however, to give thanks for things not traditionally considered to be so positive: Strangers. Hard challenges. Even negative feelings.

Studies have found that bad stuff can be important to people's happiness and that, in fact, challenges can be immensely satisfying. In honor of the upcoming season of gratitude, here are a few rather counterintuitive things to be thankful for, and the research that backs them up.

1. Strangers and small talk

About to give thanks for your smartphone for keeping you entertained during your long train commute? Don't. Research suggests you'd be happier striking up a conversation with your seatmate.

It's a hard finding to believe — isn't small talk excruciating? Not according to
a 2014 study by psychologists Juliana Schroeder and Nicholas Epley of the University of Chicago Booth School of Business. The team approached train commuters and asked some of them to spend their commute in silence and others to try to start a conversation with a stranger. Those assigned to start a conversation were more likely to expect an unpleasant commute. But the opposite happened: People who talked to a stranger during their train ride reported a more pleasant time.

The researchers followed up with a laboratory study in which people in waiting rooms were chatted up, and found that being on the receiving end of a conversational volley was pleasant, too. In other words, small talk with strangers is pleasant both for the person who initiates the conversation and for the person they choose to talk to.

"People estimated that less than 50 percent of people would be willing to talk to them if they tried," Epley said. "In fact, we never had a single person in our connection conditions who tried to talk to somebody and couldn't."

The fundamental misperception that strangers don't want to talk to you is probably why people stay silent, Epley said. But just because someone isn't talking to you doesn't mean they don't want to, he said. They're probably sitting there thinking
you don't want to talk to them.

In some ways, Epley said, conversations with strangers may be uniquely edifying. He's stumbled across people with amazing stories by striking up conversations, he said, including a man who was one of the first to flee Cuba for Miami in a homemade boat.

"A stranger has this great benefit of being just a short little interaction," Epley said. "It doesn't have to go on for years. That means in those interactions you kind of cherry-pick the most interesting thing to talk about. You take a person who is distant and you shrink the world a little bit."

2. Holiday fundraisers

Around Thanksgiving and Christmas, grocery store aisles are festooned with appeals to donate a meal to the homeless. Toy drives collect presents for needy children. Salvation Army Santas ring bells outside of mall entrances.

It can feel a bit overwhelming. But don't turn away. Studies find that supporting those in need makes people happier than spending the same amount of money on themselves.

This essential generosity is surprisingly universal. A 2013 study published in the Journal of Personality and Social Psychology surveyed people in 136 nations around the world, rich and poor alike, and found that people who had donated to charity in the past month
reported greater well-being than those who did not. The researchers estimated that the effect of having given to charity on well-being is approximately equal to doubling one's income.

In follow-up research in Canada and Uganda, people prompted to recall a time they'd spent money on themselves or on someone else. The people who recalled spending money on another person reported more happiness than the people thinking about buying something for themselves. It turns out that giving really is better than receiving.

3. New Year's resolutions

You know the drill: You promise to turn over a new leaf come January first, and you do … for a little while. What a waste of effort, right?

Nope. Just trying to do something hard might be a huge mood-booster. This is true, at least, of quitting smoking, a process that many smokers dread. A 2010 study, though, found that smokers showed a boost in mood as they tried to kick the cigarette habit, even if they were ultimately unsuccessful. Those who never tried to stop smoking during the 28-week study period
were gloomiest of all, researchers reported in the journal Nicotine Tobacco Research.

Indeed, setting ambitious goals is linked to improving happiness, even though such goals often involve greater risk than more conservative ones. A 2011 study on investing published in the
Journal of Consumer Research asked people to set goals for the return on their stock portfolio. Logically, anyone meeting their goals should be satisfied. But the study found that those who aimed high were more satisfied at meeting their goals than those who aimed low and met their goals. People seem to set their standards against a high benchmark even if their own personal goal is low, and they're disappointed when their success doesn't reach that benchmark, the researchers wrote. (The good news is that reminding people that they'd picked low goals did help improve people's moods after they achieved those goals. So if you can't aim high, at least you can remind yourself that aiming low was your choice.)

4. Not getting everything on your Christmas list

If Santa doesn't bring everything on your list this year, say thanks anyway. A large body of research finds that material goods don't make people very happy at all.

We all need our basic requirements met, of course, but once people are reasonably well-off, more money does not seem to buy more happiness. In addition, materialism is consistently linked with lower well-being than other values,
studies find. And getting new material goods is often a let-down.

"One thing that's really disappointing about material items is they often don't deliver," said Ryan Howell, a psychologist at the University of California, San Francisco, who studies consumerism and happiness. We think if we unwrap that new soufflé dish on Christmas morning, we'll become the sort of person who makes soufflés. We won't.

Likewise, people often underestimate the cost of having stuff, Howell said, from having to store it, to taking care of it, to replacing it when it's gone. People also tend to compare their things to other people's things, creating an unpleasant social competition not typically seen when people spend money on experiences, instead.

In short, a mountain of gifts to unwrap may leave you feeling a little empty. Without so much stuff, Howell said, "you lose some of the baggage that comes with these material items."

5. The holiday blues

The enforced cheer of the holiday season can feel a little bit oppressive for some. Research suggests you
embrace that melancholy.

True well-being isn't about feeling nothing but happiness all the time. Instead, negative emotions are part of what makes people mentally healthy, as
a 2012 study found. The researchers looked at 47 adults who were in psychotherapy. Each person wrote narratives about their thoughts, feelings and therapy experience. Many reported mixed feelings: Joy at a new pregnancy, for example, but simultaneous sadness over being unemployed. One woman described feeling sad and helpless, but happy that she was trying to improve her situation through therapy.

Unsurprisingly, as people reported more happy feelings and fewer sad feelings in these narratives over time, their well-being improved. But something more interesting emerged in the narratives featuring mixed happiness and sadness. Those writers got happier over time, too. Expressing mixed emotions at one time point was correlated with improved well-being later.

"The concurrent experience of happiness and sadness prospectively preceded increases in psychological well-being above and beyond the influence of happiness and sadness independently," the authors wrote. The benefit of mixed emotions on well-being isn't instantaneous, they went on, but unfolds over time. Trying to banish bad thoughts, in other words, is likely counterproductive.

"Treatment should not focus strictly on the elimination of negative emotional experience, as negative emotions may be fundamental in the process of clinical improvement," the researchers wrote.