Is this normal for Chinese/Siberian elm seedlings?

I've never attempted to grow either species from seed before, so everything is a learning process for me at the moment. I decided to try growing some of my seedlings in the ground, and others in cups(Styrofoam coffee cups with holes in the bottom). There really isn't a lot of difference in terms of size, but the ones in the ground are growing lots of side branches, despite only being about 4 inches tall, while the ones in the cups are just growing straight up. Is this fairly normal behavior, or is something else at work?

I wonder if the growth is a factor of light rather than ground v. pot?

Billy M. Rhodes wrote:I wonder if the growth is a factor of light rather than ground v. pot?

That was my first thought, but don't think it's light. Both area get almost exactly the same amount of light. Shaded in the morning until around 11 a.m. and then full sun almost until sunset. The seeds in cups aren't crowded either. If this isn't necessarily a bad thing, I won't worry about it. It just seemed sort of peculiar, and I know that plants will sometimes grow differently if there is something wrong.