Does retention of order require verbal labelling?

Older and younger adults attended to lists of either pictures or words presented one at a time. At the end of each list, they attempted to recall the serial position of each member of the list. There was a pronounced effect of primacy. No recency was observed, however, except when the very last item was tested first. The usual pictorial superiority effect was abolished when pictures were drawn from a conceptually homogenous set. It was reinstated when pictures were conceptually distinctive. Number of errors on pictures was highly correlated with the judged similarity of the items in a list. The younger subjects' performance uniformly exceeded that of the older ones; but chronological age failed to interact with any experimental variable. The results imply that pictures need not be verbally labelled in order for their serial positions to be retained.