We’ve all experienced the “winter blues” at one point. The winter season is especially harsh this year, so many of us are holed up in our homes, wrapped under layers of warm blankets and clothing and away from the rest of society. We’re cold and utterly miserable. There’s a reason why we long for warmer weather, and science shows our need for socialization might be one reason for that.

In evolutionary terms, our ancestors fared better when they lived and worked together. In greater numbers, they had a better chance of obtaining the resources they needed to survive and to protect the group from danger. As we’ve evolved over millions of years, our need to socialize became a permanent fixture in the blueprint of our brains.

Thanks to the hard work of researchers, we have a growing body of evidence that shows how our relationships with others (or lack thereof) affect us in physical and emotional ways, giving greater insight into our deep-seated need for socialization:

1. Cognitive function. A study published in Personality and Social Psychology Bulletin suggests social interactions boost cognitive performance, like memory. Researchers assessed the social interactions of 3,610 individuals and then tested their general knowledge (ie, Who is the president of the United States?) and memory. The researchers found that more socially active participants demonstrated higher cognitive abilities. This outcome was similar across all age groups.

2. Physical well-being. In addition to cognitive function, the presence or absence of a social network may even have implications on our physical health. There are a myriad of health studies that show social isolation weakens our body's ability to fight off disease, potentially leading to diabetes, heart disease, sleep dysfunction and even early mortality.

3. Emotional well-being. So having a social network is good for our brains and bodies. What about our emotional well-being? Researchers at the University of Illinois at Chicago studied changes in brain activity of socially isolated mice. They found that the brain chemicals needed to manage and reduce stress fell nearly 50 percent. Their finding suggests social isolation may trigger negative emotions or behaviors, including anxiety, stress and aggression.

While the effects of social networks or social isolation are obviously felt on an individual basis, what does this mean for society as a whole? John T. Cacioppo, Tiffany & Margaret Blake Distinguished Service Professor in the Department of Psychology at the University of Chicago, eloquently writes about the devastating effects of social isolation, particularly for marginalized groups like the elderly and minorities:

Given the projections of health care costs and the looming budget deficits, there is a critical need not only for theory and research to determine the mechanisms by which social isolation gets under the skin to affect morbidity and mortality, but for a national health care plan that both supports palliative care and promotes preventive medicine, health behavior, and healthy lifestyles to address the rising incidence of chronic disease; that recognizes and deals with stress-related physical and psychological disorders as a means of increasing physiological resilience; and that recognizes the importance of connecting lives and family.

So the next time you feel a rush of euphoria after an intimate dinner party with friends or night out with a significant other, remember all the good you’re doing for your well-being and the well-being of others.