Chimpanzee Sanctuary Northwest

Hope. Love. Home. Sanctuary

piloerection

The tell

by

Chimpanzee communication involves many overt and unmistakable expressions, from eardrum-piercing pant hoots to boisterous dominance displays, but much of what they convey is far more subtle. This morning, as the chimps were being invited to shift enclosures for breakfast, the routine ground to a halt. Negra would not come inside from the greenhouse, even when presented with bowl of peanuts. Jody kept glancing over her shoulder. And Annie sat in the doorway from the playroom, clearly interested in breakfast but unwilling to commit.

I looked towards Burrito. Sitting quietly on a bench with his hands folded in his lap, he was the picture of calm.

Or was he?

Here’s why chimpanzees would be terrible at poker. As soon as they had a good hand, their hair would stand on end and their skin would be riddled with goosebumps, betraying their excitement. Piloerection, as it is known, is the ultimate tell, a dead giveaway for a chimps’ internal state.

Behind Burrito’s otherwise calm demeanor was a simmering cauldron of testosterone, adrenaline, and pent up frustration (due in large part to Jody’s tumescent backside). The chimps could read this from a mile away. The fuse had been lit and everyone was waiting for the bomb to go off.

They were, of course, correct in their assessment, and we soon took a five-minute break from serving breakfast while Burrito rattled the cage doors and occasionally lunged at anyone nearby. Once he got it out of his system, everyone finished shifting and we got on with the day.

Your Inner Chimp

by

You’ve got a chimpanzee lurking inside of you. This might come as a surprise, I know. But you might as well embrace it because whether you like it or not, your inner chimp will always find a way to reveal himself.

Under certain conditions, your sympathetic nervous system launches a cascade of seemingly useless hormonal and muscular reactions that betray your evolutionary history. Technically, it’s called piloerection, and if you read this blog regularly you likely know what this means. Others may know it as goosebumps.

Humans tend to get goosebumps under two conditions: when we are emotionally excited, most often due to fear or surprise, and when we are cold. Why does this happen? Our chimpanzee cousins have the answer.

Many animals have an automatic response to fear that involves making themselves look bigger than they really are – think about a dog raising her hackles, a cat arching her back, or a cobra unveiling its hood. Chimpanzees respond to danger similarly by unconsciously contracting tiny muscles around their hair follicles, thereby making their hand stand on end. Piloerection can turn a small, goofy chimpanzee like Burrito into a fearsome and formidable presence.

web_crop_burrito_pilo_yh_jb_img_7786

web_burrito_pilo_yh_jb_img_7790

web_burrito_pilo_yh_jb_img_7791

Piloerection, therefore, is the body’s way of protecting itself through intimidation. So what does it have to do with cold weather? In addition to making chimps appear larger, piloerection can also help to insulate them by trapping air between the hair and skin. It’s like changing out your sweater for a nice puffy parka.

web_jody-pilo-erect-excited-drooped-lip-log-bridge-snow-youngs-hill-yh-img_1582

In humans, piloerection is a vestigial trait. Since we split from our shared ancestor millions of years ago, we’ve lost much of our body hair but retained the biological response of raising what little hair we have left when our adrenaline gets pumping. But for chimpanzees, it remains a useful way to protect themselves from both cold temperatures and the dangers of physical conflict. So the next time you get goosebumps – whether it’s because you heard something go bump in the night or because you left your jacket at home – just think of it as your inner chimp trying to get out.

Save

Save