As well as being required to make reliable assessments about sexual partners based on their physical and behavioural characteristics, animals (humans included) need to have the ability to revise these assessments based on any number of confounding environmental variables.
Plasticity refers to both variability in ecological or biological factors, and variability in behavioural or physiological reactions that animals exhibit.
Context Dependence
If anyone asks me about the most comfortable bed I’ve ever slept in, the answer is easy. After a long (long) day of hiking on a small island in Greece, I ended up in Corfu at around 1 a.m. – exhausted, dirty, and with nowhere to sleep.
The hostels were closed for the night, and, being a twenty-year-old backpacker, I was on a very tight budget. Fortunately, my parents had provided me with a credit card to use in the event of a travel “emergency,” and when I weighed the options of either snoozing on a patch of grass in a park or finding a hotel, the latter won out.
I can tell you without a shadow of a doubt that the bed in that hotel room was the most comfortable bed I’ve ever experienced.
However, I’m fairly certain that if I were magically transported back to that bed today, I would realize that it was a middle-to-low class mattress in a two-star hotel.
This illustrates the extremely important concept of context dependence, and the same principles apply to plasticity in mate selection.
Environmental Conditions
As if it weren’t taxing enough for many males in the animal kingdom to produce the vocalizations, dances, physical structures or other mating signals for females to assess, environmental conditions have a bearing on their chances of success.
On a warm summer evening at the beach after a picnic and a glass of Chardonnay we may be feeling carefree and indulgent towards members of the opposite sex.
Conversely, if it’s raining, our hair is messy, and we’re late picking up the kids from football, the exact same advances of the opposite sex may be unwelcome and annoying.
Current environmental cues can be just as important as direct sexual signals when it comes to meeting a potential partner. Sometimes it is purely astonishing that any animals manage to get it right.
This post is an adapted excerpt from my book “Wild Sex: The Science Behind Mating In The Animal Kingdom“