This is shocking, I know, but people seem to love summer. And why wouldn't they? Summer is the season when it's completely acceptable to walk around semi-naked, get trashed during the day and/or collect STDs like they're Premier League cards. But why is that? Why does a little sunshine get us all hot and bothered? And is all that summertime binge drinking the result of some irreversible biological predisposition? To find out, I got in touch with a psychologist, a sexologist and a chronobiologist.
Toine Schoutens is trained in psychiatric nursing and is currently the Director of the Dutch Centre for Research on Light and Health. Schoutens doesn't think the vitamin D we get from sun exposure has anything to do with our increased appetite for sex in the summer: "The biological explanation is actually quite simple," he says. "Originally, humans are animals accustomed to living outside and adapting to the alternation between night and day. A few thousand years ago – which isn't that long from an evolutionary point of view – we mainly lived outdoors and our reproductive rhythms were adapted to that. So if you have sex in the summer, a baby follows in spring. Then you'll have an entire warm season to raise it, which makes it easier for the baby to survive the winter."
Roelof Hut, a chronobiologist at the University of Groningen, sees things a little differently; He concedes that many animals have reproductive strategies that depend on the season but that, out of all animals, this applies the least to humans. "Compared to other animals, humans have pretty inferior seasonal rhythm. For example, the Dutch deer only feels like mating in the fall, whereas humans go at it all year long."
Still, that doesn't mean that Schoutens' theory is complete crap. "Our seasonal rhythm may be bad, but we still count on average 20 percent more births throughout the spring months as opposed to the winter months," Hut says. "In the olden days, these differences in birth rates were larger but now that we have so much artificial light, the contrast between the seasons has decreased from a biological point of view."
It would be a relief to know that my summer escapades have more to do with the preservation of my species, than just dumb horniness. Unfortunately however, according to Schoutens there also is a psychological explanation: "If the weather is nice, you go outside, get a tan and generally look a lot better. We also wear significantly less clothing, so others can easily see what kind of meat you're packing. You don't need a Masters degree in Biology to understand that that triggers our sexual impulses."
Mark Spiering, a psychologist with a specialisation in Sexology from the University of Amsterdam, agrees: "I think the main reason for our increased sex drive in the summer is simply the amount of nudity we see on the streets. More boobs, more legs, more six-packs," he says.
The fact that we are wasted most of the time also helps. As Spiering says, "alcohol clearly causes an increased interest in sex. For men this is mainly because booze increases your testosterone levels, but it works for both sexes. The only problem is that the quality of the actual sex doesn't get better. Having proper orgasms gets a lot harder. Still, our initial sex drive does increase."
Intuitively you could say that sunlight generally improves our mood, and that a good mood increases our desire to do the dirty. Surprisingly enough, Spiering says that this thesis doesn't hold up to scientific scrutiny though: "I tested this in the lab once and I found that positive emotions do not necessarily increase your sex drive or your sexual arousal." He adds that "although one could think negative emotions might lead to worse sex, a little bit of fear or stress can actually have beneficial effects for the quality of your intercourse. The assertion that a better mood automatically leads to more frequent or better sex isn't proven."
So there are definite factors that increase the desire to fuck in the summer, but what about the desire to booze it up day and night? For Toine Schoutens, there doesn't seem to be a direct correlation between warm weather and the alcohol consumption. "I think those things are largely dependent on the situation and on the drinking culture. The Nordic countries are maybe a good example here. You can translate the midsummer celebrations there as some sort of a hypomanic period where Scandinavians want to do as much as possible to make up for the dark winter months that lie ahead."
Appealing as such an explanation might be, for Roelof Hut we don't seem to have a biological disposition towards it: "Humans and fruit flies do share an enzyme, that makes us amazingly good at breaking down alcohol. But that works all year round," he says.
Meanwhile, Mark Spiering brought up an insight anyone who's never seen the inside of a school could also come up with, when he said that "it gets warmer in the summer, and you tend to get thirsty when it's warm." I guess it's reasonable to assume that our desire to get drunk is owed to the fact that we drink when we have something to celebrate, and there's just more to celebrate in the summer. If only because we're having so much more sex than the rest of the year.