At work I am VERY compeptitive, but I think you have to be in order to be a successful scientist as we have to compete with each other for research grants and to publish our work in the best journals. Outside of work I am a lot less competitive, I let my kids win games we play so that they stay interested in palying them.
Depends on how you look at it – the reviews I got for papers or research proposals so far have described me or my research in sometimes very different terms, ranging from “not feasible” and “no relevant expertise” via “decent publication record” to “very innovative” and “revolutionary”.
In my core area of interest – the application of Magnetic Resonance techniques to the study of evolution – I am not aware of much competition, nor of funders willing to provide funds that scientists would compete for. I am thus currently competing in related areas, and I do not yet have a precise idea where this will lead me.