Theodore Dalrymple on the depressing unreliability — and sometimes outright fraudulence — of far too high a proportion of what gets published in scientific journals:
Until quite recently — I cannot put an exact date on it — I assumed that everything published in scientific journals was, if not true, at least not deliberately untrue. Scientists might make mistakes, but they did not cheat, plagiarise, falsify, or make up their results. For many years as I opened a medical journal, the possibility simply that it contained fraud did not occur to me. Cases such as those of the Piltdown Man, a hoax in which bone fragments found in the Piltdown gravel pit were claimed to be those of the missing link between ape and man, were famous because they were dramatic but above all because they were rare, or assumed to be such.
Such naivety is no longer possible: instances of dishonesty have become much more frequent, or at least much more publicised. Whether the real incidence of scientific fraud has increased is difficult to say. There is probably no way to estimate the incidence of such fraud in the past by which a proper comparison can be made.
There are, of course, good reasons why scientific fraud should have increased. The number of practising scientists has exploded; they are in fierce competition with one another; their careers depend to a large extent on their productivity as measured by publication. The difference between what is ethical and unethical has blurred. They cite themselves, they recycle their work, they pay for publication, they attach their names to pieces of work they have played no part in performing and whose reports they have not even read, and so forth. As new algorithms are developed to measure their performance, they find new ways to play the game or to deceive. And all this is not even counting commercial pressures.
Furthermore, the general level of trust in society has declined. Are our politicians worse than they used to be, as it seems to everyone above a certain age, or is it that we simply know more about them because the channels of communication are so much wider? At any rate, trust in authority of most kinds has declined. Where once we were inclined to say, “It must be true because I read it in a newspaper”, we are now inclined to say, “It must be untrue because I read it in a newspaper”.
Quite often now I look at a blog called Retraction Watch which, since 2010, has been devoted to tracing and encouraging retraction of flawed scientific papers, often flawed for discreditable reasons. Such reasons are various and include research performed on subjects who have not given proper consent. This is not the same as saying that the results of such research are false, however, and raises the question of whether it is ethical to cite results that have been obtained unethically. Whether it is or not, we have all benefited enormously from past research that would now be considered unethical.
One common problem with research is its reproducibility, or lack of it. This is particularly severe in the case of psychology, but it is common in medicine too.