Psychology Atlas

How The Mind Works
Sign In
Text size
100%
Theme
Psychological Phenomena

Muller-Lyer Illusion

Perception and Psychophysics Effects

The Muller-Lyer illusion is a visual illusion in which the shaft of an arrow-like figure with two outward-pointing tails at its ends is perceived as longer than an identical shaft with two inward-pointing arrowheads, even though both shafts are actually the same length. First described by the German sociologist Franz Carl Muller-Lyer in 1889, the illusion arises from the small fin-like line segments added to each end of the shaft, and it has been shown to affect people across different cultures.

Facts
Core ClaimSourced to the subject's own account
Two arrow-like figures with shafts of equal length appear unequal because of the direction their fin lines point: the shaft ending in outward-pointing fins (an arrow tail) is perceived as longer than the shaft ending in inward-pointing fins (an arrow head). 1
First Described YearSourced to the subject's own account
1889 1
Classification
Type of PhenomenonSourced to the subject's own account
Perceptual Phenomenon 1
Connections

In Branch

Sources
1. Muller-Lyer Illusion (Wikipedia)
Wikipedia
  • Lead section, paragraph 3
    The line segment forming the shaft of the arrow with two tails is perceived to be longer than that forming the shaft of the arrow with two heads.
  • Lead section, paragraph 1
    The illusion was devised by Franz Carl Müller-Lyer (1857-1916), a German sociologist, in 1889.
  • lead section, phenomenon-kind classification
    The Muller-Lyer illusion is a visual illusion in which the shaft of an arrow-like figure with two outward-pointing tails at its ends is perceived as longer than an identical shaft with two inward-pointing arrowheads, even though both shafts are actually the same length.
View the Source
Comments (0)
No comments yet. Be the first to share a thought.
Reader Challenges (0)
No disputes yet. Spotted an error or a better source? Open the first one.