I think I've tried what Brenda said, at least once, in my early days of playing VS. But I could only get up to Level 2 and I was struggling with famine by then, so it's hard to go for Level 3 in Science before going for Level 3 in Harvesting.

One has to consider the tech points required for each levels. Levels in Harvesting demand much less tech points than say respective levels in Science or Medicine. So naturally it's logical to prioritise & secure the food source first.

However, I could only come to this realisation after playing the games many times over. It's not apparent to me in the initial games I played. So may be I am not as logical & rational as I thought I'm.