That's what I gather from: D. Fanelli, “Positive” Results Increase Down the Hierarchy of the Sciences. PLoS ONE 2010. Open access.
It's an interesting research on the reality of the generally accepted hierarchy of the sciences between harder and softer ones. Fanelli measured, among other factors, the number of positive results reported when testing a hypothesis, which broadly are likely to be more the less rigorous a science is.
However applied sciences tend to break this rule, reporting in general more positive results and with little differences for the "hard" and "soft" sciences (see fig. 2).
So, once we remove the applied sciences (labelled as "a") from the above graph, it seems pretty obvious that some biological sciences (immunology, MB and genetics, biology, medicine and pharmacology) seem to have as much procedural bias or even "cheating" as the social sciences.
Vanity, procedural sloopinness and lack of rigor are likely to exist to some extent in these disciplines. The difference is of course one of degree (see fig. 3) but from c. 70% positive results to c. 90% there is a clear difference that probably means almost 25-30% of undeserved complacency for the worst scoring disciplines (the one mendtioned above).
It is also noticeable that highly regarded Psychiatry/Psychology scores a lot worse than the general Social Sciences. While the often criticized Ecology scores very well instead.
In any case one thing is clear: the expression "it's not rocket science" has all validity, as Space Science is the one with the best results.