There are four basic ways in which this takes place.
Firstly, there’s the way in which scientific authorities and organisations promote morality to the public. Common examples are: Popular scientific figures engaging in moral debates or writing moralising newspaper commentaries flaunting their scientific authority. Scientific organisations mixing morality into their practices, such as the Nobel Committee giving out their Peace Prize, essentially a morality award, in between science awards. Scientific conferences holding side-sessions promoting certain moral views. None of this makes the moral discussions or awards themselves scientific, but by utilising scientific figures and/or a scientific backdrop it gives the impression that they are. While this is intended to promote certain moral beliefs to the public, the side-effect is that it also creates the impression within science that these beliefs are more scientific than they are, especially since those figures and organisations carry a lot of weight among rank-and-file scientists.
Secondly, there’s the way in which scientific terminology and moral terminology overlap. For example, words like ‘bias’, ‘discrimination’ and ‘equality’, words which have distinct scientific meanings, have secondary moral meanings. This not only give moral judgements the illusion of being scientific, but also can lead to equivocation between the scientific and moral meanings, making it difficult to separate the science from the non-science. An extension of that is using scientific naming practice for moral terminology, as in words like ‘xenophobia’ and ‘homophobia’. The ‘phobia’ suffix is normally used to denote mental illness, but these are purely moral judgements.
Thirdly, there’s the tendency among scientists and other intellectuals to selectively appeal to scientific facts and principles to support their moral beliefs. This creates a bias both inside and outside science.
And fourthly, there’s the way in which peer-pressures and sensitive environments exist in areas that touch upon prevailing moral beliefs, steering scientific inquiry away from certain topics and thus biasing scientific output accordingly. For example, people will commonly applaud scientific research that sets out to support prevailing moral beliefs, even when it fails (‘fighting the good fight’), yet only begrudgingly acknowledge research that sets out to disprove prevailing moral beliefs when it succeeds, and excoriate it when it fails. While sufficiently well-proven research can overcome almost any amount of resistance, as history shows, the reality is that science is difficult and often works through build-ups of vague hypotheses and incomplete observations. If the requirement for any scientist that challenges prevailing moral beliefs is perfectly documented research in order to avoid peer-condemnation and career-harm, there won’t be a lot of scientists challenging prevailing moral beliefs. Good science requires a fertile environment where ideas can be advanced and built on gradually. And most students, of course, notice this before choosing their career path. Those students who already have strong beliefs in line with prevailing morality will be drawn toward the social sciences, not just in a quest for truth, but as a vehicle to promote their beliefs. Meanwhile those students who don’t have these beliefs will recognise the social sciences as hostile and go into other fields, which leads to a vicious circle.