Answer: Confounded
Explanation: A confounded study simply means an experiment or study in which a confounding or lurking variable has been introduced which will impact or cause a distortion between both the dependent and independent variable resulting in a spurious relationship.
In the scenario above, aggressive children were subjected to aggressive movies and non-aggressive children were subjected to non-aggressive movies. A lurking or confounding variable has been introduced such that a correlation or causal relationship cannot be correctly established.