One’s acting talent does not always correlate with one’s scientific literacy. Or even one’s critical reasoning skills.

An article from the Toronto Sun quotes Hollywood actor Jake Gyllenhaal as saying the following: “I believe deeply in the unconscious. That you literally accumulate the molecules of the space that you’re in. We’re like 90% water, so naturally we are going to be affected by the moon when it’s full: if the sea is, why wouldn’t we be? That seems scientific to me.”

The actor made famous by his lead role in Donnie Darko went on to say that the molecules of his environment stick with him, and this incorporation apparently explains why he’s such a great actor. Surround yourself with cops for six months and cop molecules will become a part of you.

Sure, you may come into contact with cop dandruff but I don’t think this molecular transfer can impact your thespian skills.

As for his statement regarding the influence of the moon on the water content of our bodies, a few scientific facts deserve to be showcased (since the journalist, Liz Braun, obviously didn’t do it for us):

• We are not, “like”, 90% water; our human bodies are made up of up to 60% water. Not 90%; 60% at the most, on average. A little over half.
• The moon’s gravity does not create tidal forces inside our bodies. The Pacific Ocean is so vast that lunar gravity can act on two ends of it; the distance from your head to your feet, by comparison, is just negligible. Do you know what has a much bigger impact on the water in your body? Walking. Dancing. Driving in a car. Having sex. The sea may be affected by the moon, but we are not.
• So what about this full moon? Does it turn people into lunatics? No. Many studies have looked for correlations between any phase of the moon and pretty much anything imaginable. This meta-analysis was particularly comprehensible. Homicides? No link. Criminal offences? No link. Crisis calls? No link. When the science is thorough and the analyses are done well, there is no correlation between any phase of the moon and, well, anything else. Except nights are bit brighter during a full moon. There’s a correlation! Why do people still believe this myth? Confirmation bias. When you think the full moon makes people edgy, you notice the hits but not the misses, in much the same way that we tend to remember the good things our favourite political candidate did and not the ill-judged moves.

So, what have we learned? The human body is made up of 60% water; the moon’s gravity does not influence the water in our bodies in the same way as the oceans; and full moons don’t make us go berserk.

What you said may “seem scientific” to you, Mr. Gyllenhaal, but it’s not scientific at all. Maybe actors should stick to what they know.