n=76 also seems low to me for this type of experiment. There was a great New Yorker article titled "THE TRUTH WEARS OFF", which if I remember correctly, discussed the difficulties of reproducing scientific experiments because we underestimate the occurrences of statistical anomalies. Good time to read that article again.

http://www.newyorker.com/reporting/2010/12/13/101213fa_fact_...