Eighty-eight miles per hour: sufficient or necessary?

According to Daryl Bem, it's not necessary because events from the future can cause events in the present. His journal article, which is available in preprint [pdf] and also summarized in plain English by New Scientist, will be published by one of the prestigious psychology journals, the Journal of Personality and Social Psychology. From New Scientist:

[The paper] describes a series of experiments involving more than 1000 student volunteers. In most of the tests, Bem took well-studied psychological phenomena and simply reversed the sequence, so that the event generally interpreted as the cause happened after the tested behaviour rather than before it.

Incidentally, the mean effect size was only 0.22 so this is a fairly weak effect overall, but the effect is stronger among extraverted, sensation-seeking persons.