Researchers at the Département d’Etudes Cognitives, Institut Jean Nicod, Ecole Normale Supérieure acknowledged a difficulty with research in social learning. To count acquired behavior as cultural, two conditions need must be met: the behavior must spread in a social group, and that behavior must be stable across generations. Research has provided evidence that imitation may play a role in the propagation of a behavior, but these researchers believe the fidelity of this evidence is not sufficient to prove stability of animal culture.