<p>There is a processing fluency theory that explains it quite nicely. In short, according to this theory the symmetrical objects are pleasant as they are easier to process.</p>

<p>See Reber et al (2004) for a detailed description:</p>

<blockquote>
  <p>We propose that aesthetic pleasure is a function of the perceiver's
  processing dynamics: The more fluently perceivers can process an
  object, the more positive their aesthetic response. We review
  variables known to influence aesthetic judgments, such as figural
  goodness, figure-ground contrast, stimulus repetition, symmetry, and
  prototypicality, and trace their effects to changes in processing
  fluency. Other variables that influence processing fluency, like
  visual or semantic priming, similarly increase judgments of aesthetic
  pleasure. Our proposal provides an integrative framework for the study
  of aesthetic pleasure and sheds light on the interplay between early
  preferences versus cultural infiuences on taste, preferences for both
  prototypical and abstracted forms, and the relation between beauty and
  truth. In contrast to theories that trace aesthetic pleasure to
  objective stimulus features per se, we propose that beauty is grounded
  in the processing experiences of the perceiver, which are in part a
  function of stimulus properties.</p>
</blockquote>

<h3>References</h3>

<ul>
<li>Reber, R., Schwarz, N., &amp; Winkielman, P. (2004). Processing fluency and aesthetic pleasure: is beauty in the perceiver’s processing experience? Personality and Social Psychology Review, 8(4), 364–382. doi:10.1207/s15327957pspr0804_3 <a href="http://homepage.psy.utexas.edu/homepage/faculty/swann/docu/fall395pdocs/reber%20perceptual%20fluency.pdf">PDF</a></li>
</ul>

CC BY-SA 3.0
2012-09-15T16:05:51.653Z
2012-09-16T09:45:05.513Z
2012-09-16T09:45:05.513Z
Andrey Chetverikov
<h3>Indicator of genetic fitness argument</h3>

<p><em>There is an evolutionary psychology argument. As with most evolutionary psychology arguments, the strength of the evidence is typically a bit fuzzy.</em></p>

<p>Symmetry in many aspects of the human body is functional. Such symmetry might be seen as the natural state that arises from a healthy life and a youthful body. In contrast various genetic abnormalities, diseases, and the like  can give rise to asymmetry (e.g., scars, moles, freckles, ageing processes, deformities, etc.). </p>

<p>The argument might continue that it is adaptive for us to seek out sexual partners  who appear genetically and environmentally fit where symmetry may be one indication of this fitness. One could even extend the evolutionary argument to suggest that it would be adaptive to avoid certain types of diseased individuals in order to reduce the risk of catching some disease, where various forms of asymmetry may be indicative of this.</p>

<p>How does this explain our desire for symmetry in physical objects? The perception of beauty in the environment might be seen as an extension of perceptions of beauty in other people. </p>

<p>Little and Jones also summarise this perspective</p>

<blockquote>
  <p>One explanation for the preference for symmetrical faces comes from a
  postulated link to an evolutionary adaptation to identify high-quality
  mates (see Thornhill &amp; Gangestad (1999) for review). Symmetry in human
  faces has been linked to potential heritable fitness (‘goodgenes’)
  because symmetry is a useful measure of the ability of an organism to
  cope with developmental stress (both genetic and environmental). As
  the optimal developmental outcome of most characters is symmetry,
  deviation from perfect symmetry can be considered a reflection of
  challenges to development. Only high-quality individuals can maintain
  symmetrical development under environmental and genetic stress and
  therefore symmetry can serve as an indicator of phenotypic quality as
  well as genotypic quality (e.g. the ability to resist disease: see
  Møller (1997) and Møller &amp; Thornhill (1998) for reviews). This logic
  would lead to a preference for high symmetry mates as evolution will
  have favoured individuals who had preferences for high-quality mates
  over low-quality mates. Indeed, morphological symmetry appears to be
  related to reproductive success in many species, including humans
  (Gangestad &amp; Thornhill 1997a; Møller &amp; Thornhill 1998). For example,
  more symmetrical human males have more sexual partners than less
  symmetrical men (Thornhill &amp; Gangestad 1994) and symmetrical males are
  also more likely to be chosen as extra-pair partners (Gangestad &amp;
  Thornhill 1997b). Thus the link between symmetry and attractiveness
  may reflect that preferences for symmetrical individuals may be
  potentially adaptive.</p>
</blockquote>

<h3>Perceptual argument</h3>

<p>Enquist and Arak (1994) articulate a perceptual clarity argument. They wrote (my bolding):</p>

<blockquote>
  <p>Humans and certain other species find symmetrical patterns more
  attractive than asymmetrical ones. These preferences may appear in
  response to biological signals1–3, or in situations where there is no
  obvious signalling context, such as exploratory behaviour4,5 and human
  aesthetic response to pattern6–8. It has been proposed9,10 that
  <strong>preferences for symmetry have evolved in animals because the degree of
  symmetry in signals indicates the signaller's quality</strong>. By contrast, we
  show here that <strong>symmetry preferences may arise as a by-product of the
  need to recognize objects irrespective of their position and
  orientation in the visual field</strong>. The existence of sensory biases for
  symmetry may have been exploited independently by natural selection
  acting on biological signals and by human artistic innovation. This
  may account for the observed convergence on symmetrical forms in
  nature and decorative art.</p>
</blockquote>

<h3>References</h3>

<ul>
<li>Enquist, M., Arak, A. &amp; others (1994). Symmetry, beauty and evolution. Nature, 372, 169-172.</li>
<li>Little, A.C. &amp; Jones, B.C. (2003). Evidence against perceptual bias views for symmetry preferences in human faces. Proceedings of the Royal Society of London. Series B: Biological Sciences, 270, 1759-1763. <a href="http://www.faceresearch.org/students/papers/Little_2003.pdf">PDF</a></li>
</ul>

CC BY-SA 3.0
2012-09-10T07:58:43.397Z
2012-09-10T11:41:04.563Z
2012-09-10T11:41:04.563Z
Jeromy Anglim
<p>Most of the times, we associate symmetry with beauty. The symmetry may be in architectural/interior design for instance. Why would this be so ?</p>

CC BY-SA 3.0
2012-09-10T09:59:48.637Z
I guess we all prefer ease of mind at all times. Orderly arrangement of things makes it possible to easily remember and use the items. Thus freeing the mind of extra effort to remember or manipulate.
Muhammad Ali
CC BY-SA 3.0
2012-09-10T11:43:54.200Z
see also this question on preference for alignment: http://cogsci.stackexchange.com/questions/1250/why-do-we-prefer-visually-aligned-objects
Jeromy Anglim
CC BY-SA 3.0
2012-09-10T12:10:38.763Z
@JeromyAnglim I am not sure if adding 'evolution' as a tag is an appropriate edit. Although you provided an answer from the evolutionary perspective, it is not clear if that was the only intent of the OP's question. Maybe he meant 'why' in the mechanistic as opposed to teleological sense? Also, do we really need a Platonic 'beauty' tag? Wouldn't something like 'design' (in the sense of interior, fashion, user-experience) serve just as well for this question?
Artem Kaznatcheev
CC BY-SA 3.0
2012-09-10T12:20:41.907Z
@Artem Good points. I added a meta question about the "beauty" tag: http://meta.cogsci.stackexchange.com/questions/436/. I added the evolution tag because I figured that people following the tag might be interested in it and linking with other related questions might be useful and there was only one tag originally. But I'm not fussed if you or OP wants to remove it or add another tag.
Jeromy Anglim
CC BY-SA 3.0
2012-09-10T13:20:27.017Z
@above I'm curious about all and any kind of arguments. It seems interesting that while natural laws dictate that the entropy (a measure of disorder) should increase with time, humans try to go against it.
user13107
CC BY-SA 3.0
2012-09-10T13:33:00.557Z
I worked in architectural and landscape design when I was younger.  Symmetry isn't really the point, "order" or "evenness" is more important; symmetry is just one (relatively easy) way of achieving them.  Smooth, clean curves, even wildly asymmetric ones, are actually much more effective in landscaping.  And balanced, but asymmetric, forms in architecture.  In many ways, asymmetric forms are more attractive than simple symmetries.  The one place symmetry is extremely important for perception of beauty is in human faces and, to a somewhat lesser extent, bodies.
William B Swift
<perception><evolution><aesthetics>
Why do humans prefer symmetrical arrangement of objects?
user13107
# Why do humans prefer symmetrical arrangement of objects?

(Asked by: username_0 on 2012-09-10)

Most of the times, we associate symmetry with beauty. The symmetry may be in architectural/interior design for instance. Why would this be so ?

**Tags:** perception, evolution, aesthetics

> **Comments:**
> **username_1**: I guess we all prefer ease of mind at all times. Orderly arrangement of things makes it possible to easily remember and use the items. Thus freeing the mind of extra effort to remember or manipulate.  
> **username_2**: see also this question on preference for alignment: http://cogsci.stackexchange.com/questions/1250/why-do-we-prefer-visually-aligned-objects  
> **username_3**: @JeromyAnglim I am not sure if adding 'evolution' as a tag is an appropriate edit. Although you provided an answer from the evolutionary perspective, it is not clear if that was the only intent of the OP's question. Maybe he meant 'why' in the mechanistic as opposed to teleological sense? Also, do we really need a Platonic 'beauty' tag? Wouldn't something like 'design' (in the sense of interior, fashion, user-experience) serve just as well for this question?  
> **username_2**: @Artem Good points. I added a meta question about the "beauty" tag: http://meta.cogsci.stackexchange.com/questions/436/. I added the evolution tag because I figured that people following the tag might be interested in it and linking with other related questions might be useful and there was only one tag originally. But I'm not fussed if you or OP wants to remove it or add another tag.  
> **username_0**: @above I'm curious about all and any kind of arguments. It seems interesting that while natural laws dictate that the entropy (a measure of disorder) should increase with time, humans try to go against it.  
> **username_4**: I worked in architectural and landscape design when I was younger.  Symmetry isn't really the point, "order" or "evenness" is more important; symmetry is just one (relatively easy) way of achieving them.  Smooth, clean curves, even wildly asymmetric ones, are actually much more effective in landscaping.  And balanced, but asymmetric, forms in architecture.  In many ways, asymmetric forms are more attractive than simple symmetries.  The one place symmetry is extremely important for perception of beauty is in human faces and, to a somewhat lesser extent, bodies.  

---

## 2 answers

### Answer by username_2 on 2012-09-10. Score: 14 | Accepted answer

### Indicator of genetic fitness argument

*There is an evolutionary psychology argument. As with most evolutionary psychology arguments, the strength of the evidence is typically a bit fuzzy.*

Symmetry in many aspects of the human body is functional. Such symmetry might be seen as the natural state that arises from a healthy life and a youthful body. In contrast various genetic abnormalities, diseases, and the like can give rise to asymmetry (e.g., scars, moles, freckles, ageing processes, deformities, etc.).

The argument might continue that it is adaptive for us to seek out sexual partners who appear genetically and environmentally fit where symmetry may be one indication of this fitness. One could even extend the evolutionary argument to suggest that it would be adaptive to avoid certain types of diseased individuals in order to reduce the risk of catching some disease, where various forms of asymmetry may be indicative of this.

How does this explain our desire for symmetry in physical objects? The perception of beauty in the environment might be seen as an extension of perceptions of beauty in other people.

Little and Jones also summarise this perspective

> One explanation for the preference for symmetrical faces comes from a
> postulated link to an evolutionary adaptation to identify high-quality
> mates (see Thornhill & Gangestad (1999) for review). Symmetry in human
> faces has been linked to potential heritable fitness (‘goodgenes’)
> because symmetry is a useful measure of the ability of an organism to
> cope with developmental stress (both genetic and environmental). As
> the optimal developmental outcome of most characters is symmetry,
> deviation from perfect symmetry can be considered a reflection of
> challenges to development. Only high-quality individuals can maintain
> symmetrical development under environmental and genetic stress and
> therefore symmetry can serve as an indicator of phenotypic quality as
> well as genotypic quality (e.g. the ability to resist disease: see
> Møller (1997) and Møller & Thornhill (1998) for reviews). This logic
> would lead to a preference for high symmetry mates as evolution will
> have favoured individuals who had preferences for high-quality mates
> over low-quality mates. Indeed, morphological symmetry appears to be
> related to reproductive success in many species, including humans
> (Gangestad & Thornhill 1997a; Møller & Thornhill 1998). For example,
> more symmetrical human males have more sexual partners than less
> symmetrical men (Thornhill & Gangestad 1994) and symmetrical males are
> also more likely to be chosen as extra-pair partners (Gangestad &
> Thornhill 1997b). Thus the link between symmetry and attractiveness
> may reflect that preferences for symmetrical individuals may be
> potentially adaptive.

### Perceptual argument

Enquist and Arak (1994) articulate a perceptual clarity argument. They wrote (my bolding):

> Humans and certain other species find symmetrical patterns more
> attractive than asymmetrical ones. These preferences may appear in
> response to biological signals1–3, or in situations where there is no
> obvious signalling context, such as exploratory behaviour4,5 and human
> aesthetic response to pattern6–8. It has been proposed9,10 that
> **preferences for symmetry have evolved in animals because the degree of
> symmetry in signals indicates the signaller's quality**. By contrast, we
> show here that **symmetry preferences may arise as a by-product of the
> need to recognize objects irrespective of their position and
> orientation in the visual field**. The existence of sensory biases for
> symmetry may have been exploited independently by natural selection
> acting on biological signals and by human artistic innovation. This
> may account for the observed convergence on symmetrical forms in
> nature and decorative art.

### References

* Enquist, M., Arak, A. & others (1994). Symmetry, beauty and evolution. Nature, 372, 169-172.
* Little, A.C. & Jones, B.C. (2003). Evidence against perceptual bias views for symmetry preferences in human faces. Proceedings of the Royal Society of London. Series B: Biological Sciences, 270, 1759-1763. [PDF](http://www.faceresearch.org/students/papers/Little_2003.pdf)


---

### Answer by username_5 on 2012-09-15. Score: 7

There is a processing fluency theory that explains it quite nicely. In short, according to this theory the symmetrical objects are pleasant as they are easier to process.

See Reber et al (2004) for a detailed description:

> We propose that aesthetic pleasure is a function of the perceiver's
> processing dynamics: The more fluently perceivers can process an
> object, the more positive their aesthetic response. We review
> variables known to influence aesthetic judgments, such as figural
> goodness, figure-ground contrast, stimulus repetition, symmetry, and
> prototypicality, and trace their effects to changes in processing
> fluency. Other variables that influence processing fluency, like
> visual or semantic priming, similarly increase judgments of aesthetic
> pleasure. Our proposal provides an integrative framework for the study
> of aesthetic pleasure and sheds light on the interplay between early
> preferences versus cultural infiuences on taste, preferences for both
> prototypical and abstracted forms, and the relation between beauty and
> truth. In contrast to theories that trace aesthetic pleasure to
> objective stimulus features per se, we propose that beauty is grounded
> in the processing experiences of the perceiver, which are in part a
> function of stimulus properties.

### References

* Reber, R., Schwarz, N., & Winkielman, P. (2004). Processing fluency and aesthetic pleasure: is beauty in the perceiver’s processing experience? Personality and Social Psychology Review, 8(4), 364–382. doi:10.1207/s15327957pspr0804\_3 [PDF](http://homepage.psy.utexas.edu/homepage/faculty/swann/docu/fall395pdocs/reber%20perceptual%20fluency.pdf)


---

