Violent crime, Australia: Temperature spikes can lead to more assaults

Research shows the hotter it gets, the more chance there is of violent criminal behaviour.

Assaults, including domestic violence, peak in the summer months, Thomas More Law School lecturer in criminology and criminal justice Dr Shannon Dodd said.

"The relationship between things like assaults increase as the temperature increases," she told ACM.

"Research out of Darwin confirms there seems to be a relationship between the hotter temperature and people's behaviour, specifically in terms of acting violently or aggressively."

Similarly in NSW, research from Macquarie University, with Dr Heather Stevens as lead author, shows assaults increase in summer.

"With every one degree increase in temperature there was a 2.4 per cent increase in assaults on average per month. With every one degree that it was getting hotter, each month there were 51 more assaults," Dr Dodd said of the university's research.

IN OTHER NEWS:

Macquarie University's analysis of crime levels from 2006 to 2016 revealed an average of 5584 assaults per month during the reporting period, but in summer this jumped by 8.5 per cent to 6062 assaults.

The lowest number of assaults was in winter when there was an average of 5083 each month.

"Research showed that once you hit about 30 degrees Celsius, the daily count of assaults still increased, but they increased at a slower rate," Dr Dodd said.

"At a certain point, when it becomes a little bit too hot, people tend to retreat to their homes, to the comfort of air conditioning and then that obviously impacts those social interactions.

"Once you're heading into 31, 32, 33 degrees it may mean that people are spending more time inside and that can then impact or slow down the rate at which assaults may occur. It may actually, at a point, lead them to decrease because people simply aren't and about."

Macquarie University's data also assessed rates of theft and fraud. Autumn was the peak for thefts at an average rate of 18,736 a month compared to a low of 17,649 in winter. Fraud rates were lowest in summer at 3441 on average each month, but they jumped to 3628 in autumn.

'Hot under the collar', 'hot and bothered' and 'mango madness' may be well known expressions in the Australian language, but exactly why it happens is still up for debate. Researchers have some theories:

This theory suggests as the temperature gets hotter people become more physically irritated. They become uncomfortable and they experience heat stress, which then has an impact on their behaviour and lashing out or acting violently.

This perspective considers how people behave differently during warmer weather, and in turn this creates more opportunity to commit crime.

"If we think about the summer months in Australia, we know that young people might be out of school and on holidays," Dr Dodd said.

"Many of us are spending more time away from work and outside of home and potentially interacting more with others, drinking more alcohol and basically just socialising more frequently.

"This could create more opportunities to come into contact with others, and to have the types of interactions that could lead to things like assaults. We know that there's a clear link between alcohol consumption and drug use and violence," Dr Dodd said.

The Christmas period can be a time of increased financial strain on people and this can increase the motivation to commit assaults.

Data can help inform emergency and health authorities, to ensure resources are adequate during times when crime rates are higher.

"If we're thinking about living in climates that are continuing to get hotter, then it's important to consider what impact that might have on our behaviours," Dr Dodd said.

"If we know that in the summer months there are likely to be more assaults, then that will take greater police resources, potentially greater healthcare and hospital resources."

Dr Dodd said research could help police plan and allocate additional resources or foot patrols during days when the weather is hot and assault may spike.

On hot days, health authorities could ensure communities know what assault support is available to them if it is needed.