Most skeptics would agree with Michael Mussachia (Skeptical Inquirer Nov/Dec 1995) that "our beliefs, desires and expectations can influence, often subconsciously, how we observe and interpret things". In psychology and clinical medicine these principles are widely recognized, which is why experiments in these subjects are often carried out under blind or double-blind conditions. In a double-blind clinical trial, for example, some patients are given tablets of a drug and others are given similar-looking placebo tablets, pharmacologically inert. Neither scientists nor subjects know who gets what.

How widespread are experimenter expectancy effects in other branches of science? No one seems to know. I have attempted to quantify the attention paid to experimenter effects in different fields of science. In response, professor Richard Wiseman launched his own initiative   to "assess the impact" of my findings.

Scientific Papers on Experimenter Effects

Be More Active in Reports

Times Educational Supplement January 7, 2005
by Rupert Sheldrake

Abstract

Why are many schoolchildren still told to write up their science reports in the passive, as though experiments happened of their own accord? Many scientists abandoned this convention years ago. Watson and Crick's famous paper on the structure of DNA in Nature was in the active voice in 1953.

Blind Research: Are the Hard Sciences Immune From Experimenter Effects?

Skeptic (2003), Vol 10, No 1
by Rupert Sheldrake

Abstract

In scientific research, as in everyday life, our beliefs and biases often influence how we observe and interpret the world. In experimental psychology and clinical research, this problem is widely recognized, which is why experiments in these subjects are often carried out under blind or double-blind conditions. There is solid experimental evidence that experimenters' attitudes and expectations can influence the outcome of experiments.

Personally speaking

New Scientist, July 19, 2001
by Rupert Sheldrake

Abstract

Most scientific journals accept papers in the active voice and some, including Nature, positively encourage it. When I surveyed the current issues of 55 journals in the physical and biological sciences I found only two that still required contributors to use the passive.

How Widely is Blind Assessment Used in Scientific Research?

Alternative Therapies 5(3), 88-91, May 1999
by Rupert Sheldrake

Abstract

In everyday life, as in scientific research, "our beliefs, desires and expectations can influence, often subconsciously, how we observe and interpret things", as a recent article in the Skeptical Inquirer expressed it.(note 1) In experimental psychology and clinical research, these principles are widely recognized, which is why experiments in these subjects are often carried out under blind or double-blind conditions. There is overwhelming experimental evidence that experimenters' attitudes and expectations can indeed influence the outcome of experiments.

Experimenter Effects in Scientific Research: How Widely are they Neglected?

Journal of Scientific Exploration 12, 73-78, 1998
https://doi.org/10.1177%2F027046769701700405
by Rupert Sheldrake

Abstract

A survey of recent papers published in a range of scientific journals showed that the used of blind methodologies is very rare in the so-called hard sciences. In the physical sciences, no blind experiments were found among the 237 papers reviewed. In the biological sciences, there were 7 blind experiments out of 914 (0.8%). There was a higher proportion in the medical sciences, 6 out of 102 (5.9%), and in psychology and animal behaviour, 7 out of 143 (4.9%). By far the highest proportion (85.2%) was in parapsychology. A survey of science departments in 11 British Universities showed that blind methodologies are neither used nor taught in 22 out of 23 physics and chemistry departments, or in 14 out of 16 biochemistry and molecular biology departments. By contrast, blind methodologies are sometimes practised and taught in 4 out of 8 genetics departments, and in 6 out of 8 physiology departments. I propose a simple procedure that could be used to detect possible experimenter effects in any branch of science, by comparing the results of a given experiment conducted both under open and blind conditions.

Could Experimenter Effects Occur in the Physical and Biological Sciences?

Skeptical Inquirer 22(3), 57-58 May / June 1998
by Rupert Sheldrake

Abstract

Probably most skeptics would agree with Michael Mussachia (SI Nov/Dec 1995) that "our beliefs, desires and expectations can influence, often subconsciously, how we observe and interpret things". In psychology and clinical medicine these principles are widely recognized, which is why experiments in these subjects are often carried out under blind or double-blind conditions.


Related Research by Others

Rupert Sheldrake and the Objectivity of Science

Skeptical Inquirer, 1999, vol 23 no 5
by Richard Wisemand and Caroline Watt

Abstract

Controversial biologist Rupert Sheldrake has recently published surveys suggesting that much of the current research in science may suffer from an important methodological problem that could seriously challenge the validity of many scientific findings. This article sets in motion a project designed to assess the impact of Sheldrake's provocative findings.