Although some people may appear more playful than others, researchers say that we are all wired by evolution to play. Peter Gray, a research professor of psychology at Boston College, says, "Play primarily evolved to teach children all kinds of skills, and its extension into adulthood may have helped to build cooperation and sharing among hunter-gathers beyond the level that would naturally exist in a dominance-seeking species." In other words, for our earliest ancestors, play wasn't just about adding fun to their lives, it may have been a way of keeping the peace, which was critical for survival. There's a reason that adult play exists in modern society, says Lynn Barnett, a professor of recreation, sports and tourism at the University of Illinois at Urbana-Champaign. One theory is that we play because it's therapeutic - and there's research to back that up, she says. "At work, play has been found to speed up learning, enhance productivity and increase job satisfaction; and at home, playing together, like going to a movie or a concert, can enhance bonding and communication." Playful adults have the ability to transform everyday situations, even stressful ones, into something entertaining, Barnett says. She co-authored a study that found highly playful young adults - those who rated themselves high on personality characteristics such as being spontaneous or energetic, or open to "clowning around" - reported less stress in their lives and possessed better coping skills. Perhaps they have these attributes because they are better able to keep stress in perspective, Barnett theorises. "Highly playful adults feel the same stressors as anyone else, but they appear to experience and react to them differently, allowing stressors to roll off more easily than those who are less playful," she says.

Being a playful adult may also make us more attractive to the opposite sex, according to a study from Pennsylvania State University. Researchers there asked 250 students to rate 16 characteristics that they might look for in a long-term mate. "Sense of humor" came in first among the males and second among the females, "fun-loving" came in third for both, and being "playful" placed fourth for women and fifth for men. Lead researcher Garry Chick speculates that the attraction to playfulness may be rooted in evolution and what we value in a mate. "In men, playfulness signals nonaggressiveness, meaning they'd be less likely to harm a mate or an offspring," he said, "and in women, it signals youth and fertility." Not all adults play alike, of course. In a study published in April in the journal Personality and Individual Differences, researchers examined the complexities of adult playfulness in an effort to tease out patterns of behaviour. The researchers identified four types of playful adults: those who outwardly enjoy fooling around with friends, colleagues, relatives and acquaintances; those who are generally lighthearted and not preoccupied by the future consequences of their behaviour; those who play with thoughts and ideas; and those who are whimsical, exhibiting interest in strange and unusual things and are amused by small, everyday observations. Lead researcher Rene Proyer, a professor of psychology at the Martin Luther University Halle-Wittenberg in Germany, says that by showing how varied playfulness can be, he hopes that people will be encouraged to become more playfully engaged with others. "A less playful person can learn to be more playful, much like an introvert can learn to be a better speaker by observing the techniques extroverts use," Proyer says.

"Play is a basic human need as essential to our well-being as sleep, so when we're low on play, our minds and bodies notice," Brown says. Over time, he says, play deprivation can reveal itself in certain patterns of behaviour: We might get cranky, rigid, feel stuck in a rut or feel victimised by life. To benefit most from the rejuvenating benefits of play, he says, we need to incorporate it into our everyday lives, "not just wait for that two-week vacation every year." To identify the kind of play that would be most meaningful to you, Brown suggests thinking back to the play you enjoyed as a child and trying to connect that to your life now. For example, a person who was very active as a child may be wise to engage in recreational sports as an adult. "Play has the power to deeply enrich your adult life, if you pay attention to it," Brown says. Brittany Rouille, a 28-year-old travel blogger based in Hood River, Oregon, says she made a point of incorporating more play into her life a few years ago after her then stressful and rigid lifestyle left her depressed. "It wasn't until I reintroduced play into my life that I started to feel like myself again," she says. "Now I play every day, whether it's roller blading, painting or playing my harmonica, even if it's only for an hour, because I know how important it is for me to let go and not think about anything except for the fun thing I'm doing in that moment," Rouille says. "I find play so crucial to my well-being that I have built my life around playing outside." The Washington Post