Small point, but one I think is overlooked even among people who think statistically and proababalistically. A correlation can be high but the effect size small. When we see a correlation of 0.8 we rather automatically think "Oh, that's a big 'un! That's a major determinant, then." But it could be about something that doesn't matter much. Just to make up an example, when looking both ways to cross a street, men may look toward their dominant hand first and women their nondominant hand, and this might be near universal, cross-cultural, the whole bit. You might get a nice 0.8 on a thing like that. But it doesn't seem that it would matter much, unless we can show that men and women have different safety outcomes and this could be shown to be part of it.
We see it in environment versus inheritance discussions a lot.
I realize that was meant as a trivial and theoretical example, but it would be fascinating if that were true. Finding out that this was so strongly correlated with handedness and/or gender and not — say — the direction from which traffic was coming, ie something culturally determined would be a surprise. It would be strong evidence from biological effects on behavior.
ReplyDeleteI knew someone was going to jump on that, but I predicted someone else.
ReplyDeleteFair. My thinking is usually inclined to philosophical principles rather than statistics and probability; but I was trained in how to think this way as well.
ReplyDeleteI wasn't going to comment but I vaguely remember PSAs teaching kids to look left-right-left growing up. Maybe a boomer vs Gen X or younger thing? Did they start producing PSAs due to right handed boomer kids tragically dying while crossing the streets?
ReplyDeleteGiven the direction of travel on US roads, left-right-left means you look for approaching traffic immediately before entering the roadway.
ReplyDeleteAs a driver, left-right-left makes sense. In fact, when needing to make a left turn exiting my neighborhood to the 4-lane semi-thoroughfare, I look left-right-left... again and again, then decide to turn right because I can gauge the traffic coming from my left. Then I can get in the left turn lane and only have to guage traffic coming from the right. Then I turn into the big church parking lot, turn around and make a right turn. Two rights make a left! For more safe driving tips, don't follow me :-)
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