When was the last time you sent a thank you card?
In the age of Snapchat and Instagram, probably not for awhile. I feel like the thank you cards are a bit of a lost art. And that's not really a great thing, especially if you struggle socially.
Based on a study done by the University of South Wales, saying "thank you" and sending thank you cards makes you appear to have more interpersonal warmth. Basically, it means that sending a thank you card indicates you're a friendly and more thoughtful person.
The University of South Wales set up younger students with older mentors. Out of 70 mentees, half of them sent thank you cards to their mentors. The mentors who received thank you cards were more likely to keep in touch with those mentees.
So even if you suffer from RBF or aren't the most social person, just saying "thank you" more often can improve the impression you leave people to build longer lasting relationships.
Other studies have shown that people who are more consciously grateful and actually express gratitude are happier. Seriously, even writing down the things you're grateful for can make you a more optimistic person in a short amount of time.
Kindness is contagious, people.