Yes, this is the mechanism of cancellation of multiple causal paths. In theory one can prove, with assumptions akin to the ideal point masses and inextensible strings of physics exercises, that the probability of exact cancellation is zero; in practice, finite sample sizes mean that cancellation cannot necessarily be excluded.
And then to complicate that example, consider a professional boxer who is trying to maintain his weight just below the top of a given competition band. You then have additional causal arrows back from Weight to both eXercise and Eating. As long as he succeeds in controlling his weight, it won’t correlate with exercise or eating.
Yes, this is the mechanism of cancellation of multiple causal paths. In theory one can prove, with assumptions akin to the ideal point masses and inextensible strings of physics exercises, that the probability of exact cancellation is zero; in practice, finite sample sizes mean that cancellation cannot necessarily be excluded.
And then to complicate that example, consider a professional boxer who is trying to maintain his weight just below the top of a given competition band. You then have additional causal arrows back from Weight to both eXercise and Eating. As long as he succeeds in controlling his weight, it won’t correlate with exercise or eating.