Why is it so irresistible to put your feet up when you sit down?

Question

Why is it so irresistible to put your feet up when you sit down?

In: Biology

Answer 1

It removes stress from the back and moves you toward a fetal position. Both can be very relaxing.

Answer 2

It’s because humans lay down when they rest, and sitting down registers the brain in rest-mode. Putting the legs up is a substitute for laying down