1. Over my career I learned that the senior people in a field have an enormous influence over how well everyone else in the field treats each other. If they are collegial, helpful, open minded, fair then the field will be that way too, if they aren't it wont be. They set the tone

2. If the senior people share reagents & protocols others will follow. If they welcome new people to the field instead of treating them as interlopers, everyone will welcome new people. If they review papers fairly, then generally speaking other reviewers will tend to be fair.

3. I've also noticed that often these scientists are oblivious to the impact they have on how everyone else behaves. They often try to change the field by promoting the types of science they like, but neglect the (I think) more important aspect of how well people treat each other

4. We should not underestimate how much of a difference exists between different fields in terms of standard of behaviour. In the past I have abandoned whole areas of research that I was interested in because working & publishing in those fields was so unpleasant.

5. In contrast, some fields have been so welcoming & pleasant to work in that I decided to shift our research to be more relevant to those fields. This doesn't mean those fields were less exciting or rigorous, in fact the opposite was true, those fields just had a better culture

6. It is up to us to demand a better culture in the field we are working in, by setting a good example, by rewarding good collegial behaviour, & by calling out negative bad behaviour (failure to share data/reagents, intolerance for models that disagree w/ one's own etc.)

7. But mostly I think it's key that all of us, no matter what career stage, set a good example for today's young scientists, who are tomorrow's senior scientists, by being fair, helpful, open-minded, welcoming, & generous to other scientists in our field.