That study is wrong. Some Cheerios are male and some female and some are same-sex and some are more attracted to others than others are...but none can swim so they rush to the edge of the bowl or try to drown the little guy on the bottom. Sooner or later the little guy on the bottom will get soggy and go limp.
How am I so sure? Personal morning observation - although that may have been influenced a bit by lingering morning drowsiness.
George Carlin says: "So how do you get your Cheerios to sink? That's what the fruit is for!"