The desire to promote world peace fell into the last option.
Nearly half of the respondents had bought an EV for its green credentials.
Many felt a personal and global responsibility to curb greenhouse gas emissions - and one singled out US President Donald Trump as a reason people couldn't rely upon politicians to combat climate change.
Others expressed a sense of urgency and figured that buying an EV was one of the most practical ways that families and businesses could act for our children's future, the organisers said.
Low running costs was the main attraction of EVs for a third of respondents, mainly because of reduced fuel costs, low maintenance, and a longer life-time.
The smart technology was the EV's main pull for seven per cent of respondents, and four per cent, among them an elderly hearing-impaired couple, simply liked the quiet.
"Women and men are equally likely to buy electric, but they tend to do so for different reasons," Mckinlay said.
"Our survey showed that women were more likely to choose EVs for their green credentials, and men were more likely to rate low running costs and the smart technology as their main reason for buying."
Meanwhile, a separate study co-led by New Zealand researchers has found EVs don't interfere with pacemakers.
Electromagnetic interference (EMI) was known to disrupt the normal function of cardiac implantable electronic devices - causing effects such as resets and unwanted jolts - and EVs had been considered a potential source.
But a study by Wellington Hospital and the German Heart Centre of the Technical University of Munich found no such risk from EVs.
The researchers recruited 108 patients and paired them with one of four electric cars with the largest European market share: the BMW i3, Nissan Leaf, Tesla Model 85S, or the Volkswagen e-up!.
The participants sat in the front seat of their assigned car while it ran on a roller test bench, which allowed for maximum electromagnetic field generation, and then charged the same car in which they had sat.
The researchers then measured magnetic field strength in and around the cars during the testing, while two cardiologists independently analysed electro-cardiograms to check the pacemakers were functioning properly.
They found no evidence of disruption - something that might owe to shielding designed to prevent interference with onboard computer systems, and which could explain the low field strength inside the cars.
New Zealand and EVs
New Zealand aims get 64,000 EVs on our roads by 2021, including one third of Government vehicles, through incentives such as allowing them to use special vehicle lanes, exempting them from road user charges and subsidising projects through the LEVCF.
As of February, 6884 EVs were registered in New Zealand - half of them in Auckland - and the fleet size had grown from 192 in 2013, to 1150 in 2016 and 2980 in 2017.