Event Granularity Mismatch

Someone invites you to come along before an event. You picture a short stop and then the event itself. What actually happens is hours of preparation, transit, and waiting, all of which the other person experiences as a single, continuous thing, the day, while you experience it as a sequence of distinct phases, each one a separate decision you didn't know you were making. Nobody lied. Nobody misled anyone. And yet the gap between what was agreed to and what occurred is enormous, and it keeps happening with the same person in the same shape.

The easy explanations, bad communication, a language barrier, differing levels of consideration, don't quite fit, because the same mismatch can occur even with perfect language and total goodwill. What's actually different is something more structural: how finely each person's mind cuts a stretch of time into distinct units. This is not a personality trait in the usual sense. It's closer to a difference in resolution, and it has a name in cognitive research.

Two people can agree to identical plans and still experience completely different commitments, because one person bundles a stretch of time into a single continuous event while the other decomposes the same stretch into discrete phases, each carrying its own separate weight.

Event segmentation is not the same for everyone

Research on event perception has established that the mind does not experience ongoing activity as a smooth, undifferentiated stream. It automatically segments continuous experience into discrete units, perceiving boundaries where meaningful changes occur, and this segmentation happens whether or not a person is asked to do it deliberately [1]. Critically, this research also shows that the grain of segmentation is not fixed. The same stretch of activity can be parsed into a small number of broad units or a much larger number of fine-grained units, and which grain a person defaults to varies both by individual and by how much attention is being paid to the goal structure underlying the activity [1].

Applied to a shared plan, this means two people are not disagreeing about facts when one says "we're going to the graduation" and the other discovers a preparation phase, a transit phase, a waiting phase, and a ceremony phase. They are running the same activity through segmentation systems calibrated to different default grains. One person's honest answer to "what are we doing" is genuinely "the graduation," because that is the single unit their perceptual system generates. The other person's honest experience is a sequence of several distinct commitments, because their system is generating boundaries the first person's isn't.

Why this compounds instead of resolving with familiarity

Construal-level research adds a second layer to this. How abstractly or concretely a person represents an activity is influenced by psychological distance from it, and activities represented abstractly are naturally bundled into fewer, larger units, while activities represented concretely are broken into many specific steps [2]. A person planning their own day, one they are fully inside and not evaluating from outside, tends toward the abstract, bundled representation almost by default: "graduation day" rather than "salon, transit, ceremony, return." A person being invited into someone else's day, evaluating it from slightly outside, is more likely to represent it concretely, precisely because they are assessing it rather than simply living it. This means the mismatch is not just an individual trait difference. It is partly built into the structural difference between planning your own day and being asked to join someone else's.

This also explains why the gap doesn't close with more experience of the same person. Each time, the inviting person is still generating their own bundled representation of their own day, because that is how they experience their own activities by default. The mismatch is regenerated fresh each time, not because either person failed to learn from the last instance, but because the segmentation each defaults to is a stable processing habit, not a piece of information that gets corrected once shared.

What actually closes the gap

Since the mismatch is perceptual rather than informational in the ordinary sense, it isn't solved by better intentions or more trust. It's solved by deliberately forcing the fine-grained representation into view before agreeing, asking not "what are we doing" but "what does the sequence actually look like, step by step, with rough durations." This question works because it requires the inviting person to temporarily construct the decomposed version of their own plan, the version that matches the other person's default segmentation, rather than relying on their own naturally bundled one. It is not a matter of catching someone in an omission. It is a translation step between two different, both entirely honest, ways of parsing the same stretch of time.

What this reframes

Repeated surprise at how long a "simple" plan takes with a particular person is not evidence of bad faith, and it is not solely a language or cultural problem, even when those factors compound it. It is evidence of a stable difference in event-segmentation grain between two people, one that will keep reproducing the same mismatch until the finer-grained representation is deliberately requested in advance. Once named, it stops being a referendum on trust or consideration and becomes a specific, addressable calibration: this person's "let's do this" reliably decomposes into several more discrete phases than the phrase suggests, and knowing that is enough to ask the right question next time.

The point

When two people agree to the same plan and one is later blindsided by its actual scope, the cause is often not dishonesty, indifference, or a language gap, but a genuine difference in event-segmentation grain. Research on event perception shows the mind automatically parses continuous activity into discrete units, and the grain of that parsing, how many units a given stretch of time gets broken into, varies by individual and by how much attention is directed at the underlying goal structure. Construal-level research adds that a person planning their own day tends toward an abstract, bundled representation, while a person being invited from outside tends toward a concrete, decomposed one, meaning the mismatch is partly built into the structural difference between living a day and evaluating an invitation into it.

Because the gap is perceptual rather than a simple information gap, it regenerates each time rather than closing with familiarity, and it is not solved by trust or better intentions. It is solved by deliberately requesting the decomposed version of the plan in advance, which forces a translation between two equally honest but differently grained ways of parsing the same stretch of time.

Sources

1. Zacks, J. M., & Tversky, B. (2001). Event structure in perception and conception. Psychological Bulletin, 127(1), 3-21. On the automatic segmentation of continuous activity into discrete perceptual units, and on individual and attentional variation in the grain of that segmentation.
2. Trope, Y., & Liberman, N. (2010). Construal-level theory of psychological distance. Psychological Review, 117(2), 440-463. On how psychological distance from an activity shifts its mental representation between abstract, bundled construals and concrete, decomposed ones.