If the correlation is high, our measure is also valid. Construct validity comes at the concept a bit differently. If we know that, in theory, interpersonal openness is highly related with risk taking then we should be able to find that our measure of interpersonal openness is correlated with an established measure of risk taking. This is because if we had a perfect correlation between our measure of interpersonal openness and the measure of risk taking, one could make the argument that we are merely measuring the same thing two different ways. Instead, we want the construct validity correlation to be very much like the correlations which have been found between interpersonal openness and risk taking in previous research.
Construct validity is considered by many researchers to be the most desirable form of validity.
Ecological validity does not necessarily refer to measurement, although it can. It refers to the degree to which results found in a study also occur in the greater population. Similarly, just because our measure of interpersonal openness is reliable and valid with college students who completed it in a class does not necessarily mean that it will be reliable and valid with the population at large. Generalization is one of the more difficult problems in social science. But is it not insurmountable.