You might want to reread that (or check the actual linked research), it doesn’t say “retain” it says “remember”. It’s referring to recall specifically in children to establish when those memories start to fade or become inaccurate. The studies linked were regarding interviews with those who were still children. For example, the Cleveland & Reese study was interviewing 5½ year olds. The Tustin et al paper provides a better timeline comparison at various age stages.
You might want to reread that (or check the actual linked research), it doesn’t say “retain” it says “remember”. It’s referring to recall specifically in children to establish when those memories start to fade or become inaccurate. The studies linked were regarding interviews with those who were still children. For example, the Cleveland & Reese study was interviewing 5½ year olds. The Tustin et al paper provides a better timeline comparison at various age stages.