It's been claimed that increasing rationality increases effective altruism. I think that this is true, but the effect size is unclear to me, so it seems worth exploring how strong the evidence for it is. I've offered some general considerations below, followed by a description of my own experience. I'd very much welcome thoughts on the effect that rationality has had on your own altruistic activities (and any other relevant thoughts).

The 2013 LW Survey found that 28.6% of respondents identified as effective altruists. This rate is much higher than the rate in the general population (even after controlling for intelligence), and because LW is distinguished by virtue of being a community focused on rationality, one might be led to the conclusion that increasing rationality increases effective altruism. But there are a number of possible confounding factors:

It's ambiguous what the respondents meant when they said that they're "effective altruists." (They could have used the term the way Wikipedia does, or they could have meant it in a more colloquial sense.)
Interest in rationality and interest in effective altruism might both stem from an underlying dispositional variable.
Effective altruists may be disproportionately likely to seek to improve their epistemic rationality than are members of the general population.
The rationalist community and the effective altruist community may have become intertwined by historical accident, out of virtue of having some early members in common.

So it's helpful to look beyond the observed correlation and think about the hypothetical causal pathways between increased rationality and increased effective altruism.

The above claim can be broken into several subclaims (any or all of which may be intended):

Claim 1: When people are more rational, they're more likely to pick their altruistic endeavors that they engage in with a view toward maximizing utilitarian expected value.

Claim 2: When people are more rational, they're more likely to succeed in their altruistic endeavors.

Claim 3: Being more rational strengthens people's altruistic motivation.

Claim 1:"When people are more rational, they're more likely to pick their altruistic endeavors that they engage in with a view toward maximizing utilitarian expected value."

Some elements of effective altruism ...