Lifelong Studies of Cognitive Development= A Horror Movie

This week, we learned about the three strategies that researchers can utilize to study cognitive development across the lifespan of a human being. Those three strategies are longitudinal studies, cross-sectional studies, and cross-sequential studies. Longitudinal studies follow one person throughout the entire lifespan. It's basically a lifelong case study, where you study very specific elements of cognitive development. Though they help you see and learn a lot about the lifespan, longitudinal studies are very expensive, and your case study can "drop out" and your data becomes skewed ("drop out" basically means to die--sad times). Cross-sectional studies follow different age groups in a short period of time, usually around a year. Through this, you actually see the entire lifespan at once, and it's much cheaper than following a single person across an entire lifetime. However, your results can still be skewed, since you're studying different generations, not just different people and age groups. For example, 90-year-olds will have had, say, a worse education when they were 20 than 20-year-olds do now, and so the lifespan that you're studying could have differing results. Cross-sequential studies are sort of a blend between longitudinal and cross-sectional studies. Basically, you study a group of people with a similar characteristic (i.e. age group)for a few years, and then study a different group of people for a few years, and so on and so forth. This tries to combine the two studies while eliminating many of the inherent cons of the studies. But researchers don't realize one thing: by utilizing these strategies, they are creating a horror movie for these "participants," and the researcher is the bad guy. Imagine if you participated in one of these studies. Some random dude in a mysterious white coat follows you everywhere you go, and you just can't seem to get away from him. You're being stalked, and you can't escape. Sounds like a horror movie to me. What I'm trying to say is, these studies seem a bit unethical to me, and I would never try to organize one, let alone participate in one.