vegetation and violence. a study conducted by frances e. kuo natural resources & environmental...

Vegetation and ViolenceVegetation and Violence

A study conducted byA study conducted by

Frances E. KuoFrances E. Kuo

Natural Resources & Environmental SciencesUniversity of Illinois at Urbana-Champaign

With funding fromWith funding from• The Cooperative State Research, Education The Cooperative State Research, Education

and Extension Service, U.S. Department of and Extension Service, U.S. Department of Agriculture Agriculture

• The USDA Forest Service The USDA Forest Service Urban and Community Forestry Program Urban and Community Forestry Program on the recommendation of the National Urban on the recommendation of the National Urban and Community Forestry Advisory Counciland Community Forestry Advisory Council

• The University of Illinois at Urbana-ChampaignThe University of Illinois at Urbana-Champaign

Take home messageTake home message

Where there is less nature nearby, there is more aggression and violence.

Take home messageTake home message

• Why Study Why Study Vegetation and ViolenceVegetation and Violence??• The ApproachThe Approach• The FindingsThe Findings• So What?So What?

Presentation outlinePresentation outline

Why Study Vegetation and Why Study Vegetation and Violence?Violence?

In the inner city, In the inner city, violence levels are violence levels are high, and vegetation high, and vegetation is scarce.is scarce.

Could there be a connection Could there be a connection between scarce vegetation between scarce vegetation and high rates of violence?and high rates of violence?

Near-home nature

Less mental fatigue

Green surroundings may reduce mental Green surroundings may reduce mental fatigue…fatigue…

And less mental fatigue may be linked And less mental fatigue may be linked to less aggression.to less aggression.

Less aggression and violence

Less mental fatigue

Mental fatigue may lead to aggression byMental fatigue may lead to aggression by

• impairing the ability to handle problems impairing the ability to handle problems rationallyrationally

Mental fatigue may lead to aggression byMental fatigue may lead to aggression by

• impairing the ability to handle problems impairing the ability to handle problems rationallyrationally

• causing inattentivenesscausing inattentiveness

Mental fatigue may lead to aggression byMental fatigue may lead to aggression by

• impairing the ability to handle problems impairing the ability to handle problems rationallyrationally

• causing inattentivenesscausing inattentiveness• increasing irritabilityincreasing irritability

Mental fatigue may lead to aggression byMental fatigue may lead to aggression by

• impairing the ability to handle problems impairing the ability to handle problems rationallyrationally

• causing inattentivenesscausing inattentiveness• increasing irritabilityincreasing irritability• decreasing control over impulsive behaviordecreasing control over impulsive behavior

The demands of The demands of poverty may place poverty may place inner city residents inner city residents at high risk for at high risk for mental fatigue and mental fatigue and the aggression it the aggression it fosters.fosters.

Adding nature to the inner city may Adding nature to the inner city may reduce these risks.reduce these risks.

Near-home nature

Less aggression and violence

1 2

3

This study examines the following This study examines the following relationships:relationships:

Near-home nature

Less aggression and violence

Less mental fatigue

The ApproachThe Approach

The Robert Taylor Homes were chosen The Robert Taylor Homes were chosen as a research site becauseas a research site because• buildings are similar; only the quantity of buildings are similar; only the quantity of

nearby vegetation differsnearby vegetation differs

The Robert Taylor Homes were chosen The Robert Taylor Homes were chosen as a research site becauseas a research site because• buildings are similar; only the quantity of buildings are similar; only the quantity of

nearby vegetation differsnearby vegetation differs

• residents are randomly assigned to residents are randomly assigned to buildingsbuildings

The Robert Taylor Homes were chosen The Robert Taylor Homes were chosen as a research site becauseas a research site because• buildings are similar; only the quantity of buildings are similar; only the quantity of

nearby vegetation differsnearby vegetation differs

• residents are randomly assigned to residents are randomly assigned to buildingsbuildings

• residents have similar characteristicsresidents have similar characteristics

The participants wereThe participants were

• 145 female, heads of household, under 65 145 female, heads of household, under 65 years oldyears old

The participants wereThe participants were

• 145 female, heads of household, under 65 145 female, heads of household, under 65 years oldyears old

• from 18 buildings that varied along the full from 18 buildings that varied along the full range of amount of nearby naturerange of amount of nearby nature

The participants wereThe participants were

• 145 female, heads of household, under 65 145 female, heads of household, under 65 years oldyears old

• from 18 buildings that varied along the full from 18 buildings that varied along the full range of amount of nearby naturerange of amount of nearby nature

• recruited by interviewers going door-to-doorrecruited by interviewers going door-to-door

MethodMethod

• The 18 buildings were categorized as being The 18 buildings were categorized as being either high or low in nearby nature.either high or low in nearby nature.

Robert Taylor Homeswithout trees (barren)

Robert Taylor Homeswith trees (green)

• The 18 buildings were categorized as being The 18 buildings were categorized as being either high or low in nearby nature.either high or low in nearby nature.

• Residents’ mental fatigue was measured.Residents’ mental fatigue was measured.

MethodMethod

• The 18 buildings were categorized as being The 18 buildings were categorized as being either high or low in nearby nature.either high or low in nearby nature.

• Residents’ mental fatigue was measured.Residents’ mental fatigue was measured.

• Residents’ levels of aggressive and violent Residents’ levels of aggressive and violent behavior were measured.behavior were measured.

MethodMethod

Near-home nature

Less aggression and violence

Less mental fatigue

The relationships between all three The relationships between all three measures were then analyzed.measures were then analyzed.

Amount of vegetation outside home

Scores on test of

attention

Aggressive tactics used against partner

The FindingsThe Findings

This study found a clear link between This study found a clear link between green surroundings and reduced mental green surroundings and reduced mental fatigue.fatigue.

Near-home nature

Less mental fatigue

More nature near home, less More nature near home, less mental fatiguemental fatigue

Mean number correct on attention measure

Greenness rating of residence

55

44

greenbarren

4.54.5

More correct = less fatigued attention

And residents with less mental fatigue And residents with less mental fatigue reported less aggression and violence.reported less aggression and violence.

Less aggression and violence

Less mental fatigue

Finally, there was a clear link between Finally, there was a clear link between having near-home vegetation and less having near-home vegetation and less aggression and violence.aggression and violence.

Less aggression and violence

Near-home nature

Mean Ratings of Aggression Against Partner During Past Year in Green Versus Barren Conditions

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

OverallAggression

PsychologicalAggression

Violence Mild Violence Severe Violence

Mean Ratings of Aggression

BarrenGreen

Nearby nature leads to less Nearby nature leads to less violence and aggressionviolence and aggression

More aggression

Less aggression

Range of Aggression Tactics Used Against Partner in Lifetime in Green Versus Barren Conditions

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

OverallAggression

PsychologicalAggression

Violence Mild Violence Severe ViolenceMean Ratings of Range of Aggression

BarrenGreen

Nearby nature leads to a smaller Nearby nature leads to a smaller range of violence and aggressionrange of violence and aggression

More types of aggression

Fewer types of aggression

In sum, In sum,

In sum, individuals living in In sum, individuals living in green surroundings were green surroundings were less mentally fatigued,less mentally fatigued,

In sum, individuals living in In sum, individuals living in green surroundings were green surroundings were less mentally fatigued, and less mentally fatigued, and less aggressive and violent.less aggressive and violent.

So What?So What?

Because violence begets Because violence begets violence, reducing violence violence, reducing violence now is likely to reduce now is likely to reduce violence in future violence in future generations.generations.

Suggestions for individualsSuggestions for individuals

If angry, take a walk If angry, take a walk in green in green surroundings.surroundings.

Spend time in Spend time in natural settings to natural settings to revive your revive your ability to focus on ability to focus on tasks that demand tasks that demand concentration.concentration.

Suggestions for individualsSuggestions for individuals

Encourage children Encourage children to use nature for to use nature for relaxing and “cooling relaxing and “cooling off.”off.”

Suggestions for individualsSuggestions for individuals

Encourage city Encourage city planners to plant planners to plant trees in the inner trees in the inner city.city.

Suggestions for individualsSuggestions for individuals

Support city Support city policies for policies for maintaining trees.maintaining trees.

Suggestions for individualsSuggestions for individuals

When possible, When possible, plant and care for plant and care for trees near your trees near your home.home.

Suggestions for individualsSuggestions for individuals

City planners and City planners and arborists should arborists should note: the location note: the location of vegetation of vegetation matters.matters.

Caring for trees Caring for trees means caring for means caring for people!people!

To share this information To share this information with otherswith others

• • Copies of this presentation and other, written Copies of this presentation and other, written materials for nonscientific audiences may be obtained materials for nonscientific audiences may be obtained at <www.lhhl.uiuc.edu> at <www.lhhl.uiuc.edu>

• • To quote this information in print, please consult the To quote this information in print, please consult the original scientific journal article: original scientific journal article: Kuo, F.E. & Sullivan, W.C. (2001). Aggression and violence in Kuo, F.E. & Sullivan, W.C. (2001). Aggression and violence in the inner city: Impacts of environment via mental fatigue. the inner city: Impacts of environment via mental fatigue. Environment & BehaviorEnvironment & Behavior, 33(4), 543-571., 33(4), 543-571.

Available at www.lhhl.uiuc.eduAvailable at www.lhhl.uiuc.edu

On details of the original studyOn details of the original studyKuo, F.E. & Sullivan, W.C. (2001). Aggression and violence in the inner city: Kuo, F.E. & Sullivan, W.C. (2001). Aggression and violence in the inner city: Impacts of environment via mental fatigue. Impacts of environment via mental fatigue. Environment & BehaviorEnvironment & Behavior, 33, 543-, 33, 543-571.571.

On nature and mental fatigueOn nature and mental fatigueKaplan, R. (1984). Wilderness perception and psychological benefits: An Kaplan, R. (1984). Wilderness perception and psychological benefits: An analysis of a continuing program. analysis of a continuing program. Leisure ScienceLeisure Science, 6, 271-290., 6, 271-290.

Kaplan, S. (1995). The restorative benefits of nature: Toward an integrative Kaplan, S. (1995). The restorative benefits of nature: Toward an integrative framework. framework. Journal of Environmental PsychologyJournal of Environmental Psychology, 15, 169-182., 15, 169-182.

To learn more:To learn more:

On mental fatigue and aggressionOn mental fatigue and aggressionCaprara, G.V., Renzi, (1981). The frustration-aggression hypothesis vs. Caprara, G.V., Renzi, (1981). The frustration-aggression hypothesis vs. irritability. irritability. Recherches di Psychologie SocialeRecherches di Psychologie Sociale, 3, 75-80., 3, 75-80.

Kaplan, S. (1987). Mental fatigue and the designed environment. In J. Kaplan, S. (1987). Mental fatigue and the designed environment. In J. Harvey & D. Henning (Eds.), Harvey & D. Henning (Eds.), Public environmentsPublic environments. Edmond, OK: . Edmond, OK: Environmental Design Research Association, pp. 55-60.Environmental Design Research Association, pp. 55-60.

Stanford, M.S., Greve, K.W., Dickens, T.J. (1995). Irritability and Stanford, M.S., Greve, K.W., Dickens, T.J. (1995). Irritability and impulsiveness: Relationship to self-reported impulsive aggression. impulsiveness: Relationship to self-reported impulsive aggression. Personality and Individual DifferencesPersonality and Individual Differences, 19, 757-760., 19, 757-760.

To learn more:To learn more:

Other questions?Other questions?

Contact Frances E. Kuo, Ph.D. (fekuo@uiuc.edu)Contact Frances E. Kuo, Ph.D. (fekuo@uiuc.edu)

The University of Illinois at Urbana-ChampaignThe University of Illinois at Urbana-Champaign

Landscape and Human Health LaboratoryLandscape and Human Health Laboratory

1103 S. Dorner Drive, MC-6361103 S. Dorner Drive, MC-636

Urbana IL 61801Urbana IL 61801