Many bankers think they can read their customers like an open book, but in fact they may need to put in some extra research time.

According to a new study by the Boston consulting firm Celent, banks overestimate how much their customers want to use smartphones to handle banking tasks.

The disconnect is not a fatal flaw, said Bob Meara, an analyst at Celent. But it suggests that many banks need to rethink their entire approach to learning about their customer base.