My friend knows how to wiggle his right ear only, and I tried to wiggle my ears as well, but he told me that I can't learn it, it has to be natural. Is there any study on this, or is it actually possible to learn how to wiggle my ears?
Much to my surprise, it looks like this is probably true.
According to a database on inheritance maintained by Johns Hopkins University and the National Institute of Health, it would appear that ear wiggling is in fact an autosomal dominant trait. That means that if a person has at least one dominant version of the ear wiggling gene, then that person should be able to wiggle his/her ears. (If anyone would like a to brush up on dominance, Wikipedia (of course) has a decent article.)
It's worth noting, however, that I could find no other published information about this alleged gene. It looks like there's a gene there, but we don't yet have it mapped, and it's not being actively studied.
I did find an interesting article published by Discovery that doesn't talk about genetics, but rather about the physical mechanism for ear movement (among other aural phenomena). Here's the part about wiggling:
"The mechanism behind ear movements is sophisticated," said Bastiaan ter Meulen, who led the ear wiggling study.
Ter Meulen, a researcher at Erasmus MC, a university medical center in Rotterdam, the Netherlands, added that, unlike other facial muscles, ear muscles have their own accessory nucleus -- a control area for muscle function -- in the brainstem.
"Compared to animals, especially bats and cats, this nucleus is rather small in humans," he said.
He explained to Discovery News that a muscle involved in eye movement also directly controls ear motion. That's why when we look left or right, our ears slightly withdraw on both sides.
Breathing and swallowing are also linked to ear movement through muscles and neuronal pathways.
Ter Meulen and his team made these determinations after conducting an EEG, or brain wave test, on a 43-year-old woman who lost consciousness and experienced rhythmic bursts of ear movement.
So if we assume that the gene does exist, then unless one has the gene, it's true, one cannot "learn" to wiggle one's ears. That's not to say, however, that a person with the gene is just going to be able to wiggle away. As the Discovery article implies, it doesn't look like it's a movement that comes particularly naturally to humans - it might still wind up being a learned process for some people. Point being, it's entirely possible one can "learn" to wiggle, but it looks like one probably needs a specific dominant gene to do so.
Edit: As Fabian let me know, the original study I initially found is freely available online. The .pdf can be found here, the study is on pages 620-621. Worth noting is that the author of the study essentially gives the same "this study is small and not necessarily indicative of anything" warning that I did above:
Since the material is small, we must not, however, attach too much importance to these figures. Even if these results appear to indicate dominance with a relatively high penetrance, the results must nevertheless be verified on a larger material before they can be considered as convincing.