Recently saw a study that connected the size of a hand of a person with his/her height. The regression looked reasonably linear.
There are also studies that show the connection between blood-pressure between two arms of a person and health. That makes me think there might be variety of correlations that we may look at, some simple questions to ask may be,
“Does the shoulder length of a person correlate with height? or weight?”
“How does BMI correlate with height?”
“what about the legth of a person’s foot and height?”
We know there is a correlation but how good is it? It would also be interesting to see is their is something special about the outliers.