It depends on the action. Acting without reason implies blind faith, which is (imo) not a desirable thing.
By the time one is college age, reasoning ability should already be functional.

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"Every morning in Africa, a Gazelle wakes up. It knows it must run faster than the fastest lion or it will be killed. Every morning a Lion wakes up. It knows it must outrun the slowest Gazelle or it will starve to death. It doesn't matter whether you are a Lion or a Gazelle... when the sun comes up, you'd better be running." -anonymous