What is more energy expensive--a smile or a frown?

Question

I know there is much uncertainty on which uses more muscles and which is more energy requiring.

If you have any values for the actual energy expenditures of each, I would greatly appreciate it if you present it.

thank you. There's just so much confusion around it. :)

Answer 1

A frown uses 41 muscles whereas a smile only uses 17   :)

Answer 2

a smile uses less muscles  

Answer 3

A frown takes more muscles, but a smile takes more energy.

Answer 4

a frown, since it uses more muscles

Answer 5

a smile

Answer 6

A smile will get people to help you, conserving your own energy.  Remember that no one smiled in oldtime photos that required timed exposures, because a genuine smile can be held only an instant.  Some people can genuinely frown all day long.