Concurrent validity is a type of evidence that can be gathered to defend the use of a test for predicting other outcomes.
[1] In both cases, the (concurrent) predictive power of the test is analyzed using a simple correlation or linear regression.
Reduced motivation and restriction of range are just two possible biasing effects for concurrent validity studies.
Convergent validity refers to the observation of strong correlations between two tests that are assumed to measure the same construct.
It is the interpretation of the focal test as a predictor that differentiates this type of evidence from convergent validity, though both methods rely on simple correlations in the statistical analysis.