Weird illusion in which adding weight to something makes it feel lighter

Originally published at:

1 Like

… and Chaz Firestone Johns of Hopkins University

Or maybe: and Chaz Firestone of Johns Hopkins University.


It’s important to mention that the top box was significantly heavier than the other two (250g vs 30g).

(I first tried it with a stack of quarters assuming it just required three identical objects and it didn’t work…)

1 Like

Oops… two PhD prof.'s and their grad student couldn’t even be bothered to reread their tiny 12-page report and keep their conclusions straight when summarizing the second and third experiment.
As in Experiment 1, subjects reported that A+B+C felt heavier than A (90%, p<.001; Figure 3), even when they didn’t “lift” the boxes at all but simply felt their pressure against their passively open palms. This suggests that neither differences in grasp posture nor in lifting force explain the impossible experience of one object feeling heavier than a group that includes it.” (p.10/ex.3, and almost exact same wording on p.8/ex.2.)

1 Like

He’s not heavy.
He’s my brother with my sister on his shoulders.


I wonder if some language ambiguity along the lines of heavy vs dense is relevant. Or perhaps having a larger surface area to grab/maneuver feels easier to lift/manipulate.

Ive often noticed that a small object with high density feels heavier than a larger object of comparable density. As if you underestimate the weight of smaller objects before picking them up, and then the weight feels heavier than expected.

For me this works for heavy materials (like metals) but not for lighter stuff like wood.

Does anyone know what new result is covered in the paper? I thought the basic illusion was known. (I was shown the effect a couple of years ago by Art Shapiro, whose non-actually moving diamond was on BB a few days ago.)

1 Like

until it reaches a certain size. maybe the width of your arms. once you get torque ( that sounds clever right, i don’t know the reason why ) in there - even light loads can feel unmanageable

I’ve certainly observed this in the past. I was hoping for some explanation for this. It definitely seems to have something to do with density. Obviously before you lift something a subconscious process is deciding how much force to apply. So I just assume that for things that aren’t really heavy (that is, they aren’t straining our capacity to lift them) our perception of weight is more about the relationship between how hard it was and how hard some we “thought” it was going to be.


This topic was automatically closed after 5 days. New replies are no longer allowed.