title: "Positive" results increase down the Hierarchy of the Sciences.
abstract: The hypothesis of a Hierarchy of the Sciences with physical sciences at the top, social sciences at the bottom, and biological sciences in-between is nearly 200 years old. This order is intuitive and reflected in many features of academic life, but whether it reflects the "hardness" of scientific research--i.e., the extent to which research questions and results are determined by data and theories as opposed to non-cognitive factors--is controversial. This study analysed 2434 papers published in all disciplines and that declared to have tested a hypothesis. It was determined how many papers reported a "positive" (full or partial) or "negative" support for the tested hypothesis. If the hierarchy hypothesis is correct, then researchers in "softer" sciences should have fewer constraints to their conscious and unconscious biases, and therefore report more positive outcomes. Results confirmed the predictions at all levels considered: discipline, domain and methodology broadly defined. Controlling for observed differences between pure and applied disciplines, and between papers testing one or several hypotheses, the odds of reporting a positive result were around 5 times higher among papers in the disciplines of Psychology and Psychiatry and Economics and Business compared to Space Science, 2.3 times higher in the domain of social sciences compared to the physical sciences, and 3.4 times higher in studies applying behavioural and social methodologies on people compared to physical and chemical studies on non-biological material. In all comparisons, biological studies had intermediate values. These results suggest that the nature of hypotheses tested and the logical and methodological rigour employed to test them vary systematically across disciplines and fields, depending on the complexity of the subject matter and possibly other factors (e.g., a field's level of historical and/or intellectual development). On the other hand, these results support the scientific status of the social sciences against claims that they are completely subjective, by showing that, when they adopt a scientific approach to discovery, they differ from the natural sciences only by a matter of degree.
authors.affiliation: INNOGEN and ISSTI-Institute for the Study of Science, Technology & Innovation, The University of Edinburgh, Edinburgh, United Kingdom. dfanelli@staffmail.ed.ac.uk
authors.forename: Daniele
authors.initials: D
authors.lastname: Fanelli
mesh_terms: D001690:Biological Science Disciplines / Q000592:standards; D008722:Methods; D010811:Natural Science Disciplines / Q000592:standards; D011642:Publications / Q000592:standards / Q000639:trends; D012106:Research / Q000592:standards / Q000639:trends; D012586:Science / Q000145:classification / Q000379:methods / Q000592:standards*; D012942:Social Sciences / Q000592:standards
references.citation: Behav Res Methods. 2009 Nov;41(4):1149-60
references.pmid: 19897823
references.citation: Eur J Cancer. 2007 Nov;43(17):2559-79
references.pmid: 17981458
references.citation: PLoS Med. 2005 Aug;2(8):e124
references.pmid: 16060722
references.citation: J Urol. 2006 Jul;176(1):263-6
references.pmid: 16753417
references.citation: Nature. 2009 Mar 5;458(7234):30
references.pmid: 19262652
references.citation: Clin Neuropsychol. 2006 Feb;20(1):27-38
references.pmid: 16393919
references.citation: Philos Soc Sci. 1992 Mar;22(1):5-27
references.pmid: 11651287
references.citation: Behav Processes. 2001 May 3;54(1-3):155-165
references.pmid: 11369467
references.citation: Q Rev Biol. 1987 Dec;62(4):397-409
references.pmid: 3328215
references.citation: Account Res. 2005 Jul-Sep;12(3):225-40
references.pmid: 16634173
references.citation: Pers Soc Psychol Rev. 1998;2(3):196-217
references.pmid: 15647155
references.citation: Oecologia. 2002 Aug;132(4):492-500
references.pmid: 28547634
references.citation: Health Technol Assess. 2000;4(10):1-115
references.pmid: 10932019
references.citation: Nucl Instrum Methods Phys Res A. 2007;571:195-198
references.pmid: 18418467
references.citation: PLoS One. 2009 May 29;4(5):e5738
references.pmid: 19478950
references.citation: Bull Med Libr Assoc. 1967 Jan;55(1):75-84
references.pmid: 6016373
references.citation: Biol Rev Camb Philos Soc. 2002 May;77(2):211-22
references.pmid: 12056747
references.citation: Behav Anal. 2008 Spring;31(1):61-6
references.pmid: 22478502
references.citation: Health Psychol. 2001 Jan;20(1):76-8
references.pmid: 11199069
references.citation: Am Nat. 1999 Aug;154(2):220-233
references.pmid: 29578786
references.citation: J Biomech. 2008;41(8):1623-31
references.pmid: 18460409
references.citation: Proc Natl Acad Sci U S A. 2006 Mar 28;103(13):4940-5
references.pmid: 16543380
references.citation: PLoS One. 2008 Aug 28;3(8):e3081
references.pmid: 18769481