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. ([email protected])Contact Frances E. Kuo, Ph.D. ([email protected])
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