Absent-Mindedness: Why You Forget to Do the Thing You Meant to Do

Absent-mindedness is a failure at the junction between attention and memory, and Daniel Schacter's 1999 classification of memory's seven sins places it there deliberately: transience is memory fading over time, blocking is a memory that will not come when called, and absent-mindedness is the case in which the memory was never properly formed or the stored intention never fired, because attention was elsewhere at the critical moment. The keys were not lost from memory; their location was never encoded, because they were put down on autopilot during a phone call.

Two kinds of lapse share the name. The first is at encoding: a routine action carried out without attention leaves little or no trace, so there is nothing to retrieve later. The second is at retrieval of an intention, what psychologists call prospective memory: you formed a plan to do something at a future moment, the moment came, and the plan did not come with it. The milk is not bought because, when the shop went past, the mind was on the day's meeting; the intention was intact and its cue did not reach it.

James Reason's work on action slips describes the first kind in detail. In a diary study published in 1979, 35 volunteers recorded every "action not as planned" over two weeks, and the slips fell into a few recurring forms: carrying on with a habitual sequence when a different one was intended, as in driving the usual route to work on a Saturday; losing track of where you are in a sequence, as in adding the sugar twice; and omitting a step after an interruption. Reason's analysis, developed in his 1984 chapter on lapses of attention, is that well-practiced actions run automatically and need an attentional check where the routine could branch; the slip happens when attention is elsewhere.

Prospective memory has its own laboratory. Gilles Einstein and Mark McDaniel's 1990 paradigm, which the demo above borrows, embeds the intention in an ongoing task and waits to see whether the cue triggers it. Two findings from that line of work describe absent-mindedness well: intentions tied to a distinctive event are retrieved more reliably than intentions tied to a time, and people allowed to construct an external reminder did better than people relying on memory alone. The intention lives or dies by its cue, and the cue works best when it is in the world rather than in the head.

Absent-mindedness has two founding literatures rather than one experiment: James Reason's naturalistic studies of action slips, and Einstein and McDaniel's laboratory paradigm for prospective memory. Schacter's 1999 paper in American Psychologist, "The seven sins of memory," named the category and drew the two together.

Reason's 1979 chapter, "Actions not as planned," reported a diary study in which 35 volunteers kept a record of their slips of action over two weeks. The slips clustered into types: repetitions of a step already done, omissions after an interruption, intrusions of a strong habit into a different task, and reversals in which the right actions were performed on the wrong objects. Reason argued that the slips were the price of automatization: skilled routines run largely outside attention, which frees the mind for other things, and a routine will carry on in its usual direction unless attention intervenes where it should have changed course. His 1984 chapter in Varieties of Attention set out the model in full.

Einstein and McDaniel's 1990 paper in the Journal of Experimental Psychology: Learning, Memory, and Cognition asked whether prospective memory, remembering to do something at a future moment, declines with age the way remembering past events does. Young and older adults performed a short-term memory task and were told to press a key whenever a target word, rake for some of them, appeared. In two experiments the older adults showed reliable deficits on the retrospective tests of free recall and recognition, and no deficit on the prospective task; performance on the two kinds of memory was not reliably related across people. Participants allowed to make an external reminder from materials on the desk did better than those who were not, and an unfamiliar target word was easier to act on than a familiar one.

The paradigm became the standard way of studying prospective memory, and later work refined the picture: time-based intentions, which have no external cue, do show age differences that event-based intentions often do not, and dividing attention during the ongoing task raises the miss rate in everyone. The demo on this page is the event-based version with a visible response option, the easiest form of the task.

The pattern appears wherever a routine runs without attention or an intention waits for a cue that never comes. The rows are illustrations, not findings from the cited studies.

Because the failure is in attention rather than storage, the counters work on cues and routines rather than on trying harder to remember.

• Put the cue in the world. A note on the door, the item by the keys, a bag on the passenger seat: Einstein and McDaniel found that people who could build an external reminder outperformed those who relied on memory.
• Tie intentions to events, not times. "When I pass the pharmacy" gives the intention a trigger; "at four" gives it nothing to attach to.
• Make a place for the things you lose. If the keys always go on the hook, encoding the location becomes unnecessary, because the routine supplies it.
• Attend at the branch points. Reason's slips happen where a routine could go two ways. Saying the step aloud, or pausing at the turn, puts attention back where the check is needed.
• Record the act inside the act. A pill organizer, a checklist ticked as you go, a photo of the stove before you leave: the record is made by doing the thing, so there is nothing extra to remember.

Absent-mindedness is one of several ordinary memory failures, and its neighbors differ in where the failure sits.

• It is not the tip-of-the-tongue phenomenon, in which a well-encoded memory is temporarily unreachable despite full attention. That is Schacter's blocking; absent-mindedness is the case in which attention was never on the thing at all.
• It is not cue-dependent forgetting, in which a memory is available but the cues present at retrieval do not match the ones present at encoding. The two overlap in prospective memory, where a missed cue is the failure, but cue-dependent forgetting concerns memories that were encoded with attention.
• It is not the Google effect, the tendency to remember where to find information rather than the information itself. That is a strategy about what to store; absent-mindedness is a lapse in storing or acting at all.