It may not much matter. You didn't mention your son's age, but you did mention something about college so I am going to go out on a limb that he's of traditional college age and under the age of 24.
In that case, if it's on his return or yours, it will be taxed at the same rate since the unearned income of a "child", which includes most individuals with living parents up to age 24 will be taxed at the (presumably) higher rate of the parent.
The IRS won't care much which of you claims it as long as someone claims it and pays the appropriate tax. If he is 25 years of age or older, then I would report it on your tax return unless your son makes more money and is in a higher tax bracket. The IRS will never complain if the decision you make gives them the benefit of the higher tax. They are unlikely to compare two tax returns to see if they got the most money anyway, but their computers will look to see that the interest is reported somewhere.
Sometimes you will find conflicting answers because no one really knows, or there is no single correct way to do something. It would be nice if tax worked a little more like "this is the way", but it doesn't always. It's not like engineering 🙂
