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I disagree, both from my experience interviewing at top PhD programs across the country and from the perspective of professors in my program.</p>
<p>It’s a disadvantage in biology, although not a crippling one, to apply straight out of undergrad. My entering PhD class was about half students straight from undergrad and half people who had taken time off, mostly to do tech work. A significant percentage of people who go on to PhD programs in biology do not come straight from undergrad.</p>
<p>From the perspective of the program, it makes sense to accept people who are mature and committed to finishing a PhD. Looking at the students in my program, students who come straight from undergrad are less likely to have decided on a specific research area, and are more likely to rotate through more labs or to change labs after prelims – although they are younger when they start their degrees, their time to degree is greater than students who take time off. And FWIW, time to degree is decreasing across the board – my program and others are taking conscious steps to reduce average time to degree from 6 years to 5.5.</p>
<p>Grad school is a marathon, not a sprint. There’s no inherent advantage, and quite a few inherent disadvantages, to trying to get through your training as quickly as possible.</p>
<p>Anyway, my point with regard to the OP was not that finishing in three years is impossible, or a kiss of death, but that it requires planning ahead. I don’t think that’s terribly controversial.</p>