I can confirm the science comments. Wore a suit (and a clean haircut) to the first of my interviews and felt overdressed. Relaxed the garb for the next three interviews and felt much more at ease. Got into all but the first of the schools. Science people sway much more towards dressing "nice" (i.e. clean, what I would describe at attractive-, but not formal-looking) over business or even business-casual. No point wearing a $100 shirt if you're going to get drops of iron or acid on it.I wear a suit for weddings, funerals, and banquets. I would wear one for some interviews, but if I were interviewing for a science position, I'd probably go with a suit but no tie, just so it's clear. I don't terribly mind wearing suits, and even enjoy looking smart in that way from time to time, but I would not long stay in a position that required me to wear one daily. Same goes for a cowboy hat.