A colleague of mine has recently posted an excellent blog regarding the recent scandal arising out of the putative relationship between vaccinations and autism. Public views about science vary a lot but there are those who would point to this scandal (and others) to support an anti-science viewpoint. They might conclude that by being less than 100% perfect, science loses all credibility. Those holding such a 'holier than thou' position should perhaps examine their own lives and consider how perfect their behavior has been. Anyway, I have some comments regarding my colleague's blog:
Lest a gratuitous co-author (i.e., someone insisting on being added to the author list, or accepting an invitation to be a co-author on a paper about which they know little or nothing) choose to deny any responsibility for the content of any paper on which they are a co-author, they should realize that if they have any positive scientific reputation, they're lending their credibility to that paper. If they're co-authors on a fraudulent paper that gets published, they'll inevitably suffer a significant loss of credibility among their peers. No amount of rationalizing can wash their reputation fully clean after that.
That said, however, there has to be an element of trust in a scientific partnership. It's an ideal, but for the most part, individual scientists on a paper with multiple authors don't actually review and replicate everything in every paper. That's simply not a realistic obligation. Nor is it plausible to add a "statement of work" for each author to the paper. In the real world of scientific collaboration, individual authors bring different skills and efforts to the whole, and individual scientists legitimately may have only a superficial understanding of the specialty knowledge brought to the project by their collaborators. If don't trust your colleagues, you'd have to know everything about everything and do everything yourself. Why bother with collaborators in that case?
Funny thing about trust: it can be hard to gain and easy to lose, but as I see it, the default position should be to trust until something happens to violate that. If you trust no one until they've proven their trustworthiness in some sort of a crucible, you'll have a very limited set of colleagues. Anyone can be victimized by a collaborator who turns out to be untrustworthy. It's not fair that some scientist would take a serious hit to their credibility if they were so victimized, but the world isn't necessarily fair! You only have control over things that you do, so it behooves any scientist to behave with integrity, irrespective of what anyone else does.
It's unfortunate that science has such scandals, but it simply reflects the undeniable fact that science is a human endeavor, with all that that implies. Not everyone will always choose to abide by its standards. Science as a whole isn't tarnished by the scandals perpetrated by the deeds of an unethical few. But as my colleague has said, we all feel a collective revulsion and sadness when such things come to light. And there are those who will seize on such events to attempt to discredit science as a whole.
The scandal does underscore the risk you take as a "gratuitous" co-author, and I believe, like my colleague, that the benefit of adding another paper to your CV doesn't outweigh that risk. I always trust my collaborators to do their work with high integrity and I'd be shocked and ashamed to find that a co-author had done something so contemptible. But there's always a finite possibility it could happen to me. If something like this happened to some scientist I know, then my default assumption would be they weren't truly responsible for the ethical lapse of another. This doesn't contradict with my assertion that they're formally responsible for the content of a paper on which they're a co-author, however. Real life can be complicated ...