"That probably piqued my initial interest in happiness - how do people get happy? What is happiness about? What goes into making people happy?"
A colleague at the university then told Dr Chadwick about "savouring strategies" which sparked her thirst to find out more.
While past research has examined how people savour major but fleeting events, such as going on holiday or receiving a high mark at school, Dr Chadwick wanted to investigate the effect of the minor and everyday positive events that make up life.
So she enlisted more than 400 young people aged between 13 and 15 in the Bay of Plenty and 1500 adults from across New Zealand and overseas, and grouped them into four overall strategies.
"I gave them questionnaires on what they do on a daily basis to 'savour'. So I asked them what were the positive things they experienced."
She gave participants a list of 26 examples of positive experiences - such as having a good meal with your folks or watching a good film.
The participants were asked how often those experiences happened in one month, how intense the feeling of happiness was and how they responded to the positive experiences.
"Whether they thought, 'Yeah, I'm a really fortunate person', and so that's where all the savouring strategies came in, how they were responding to all the positive events in their life."
Dr Chadwick, who moved to New Zealand from Colorado nine years ago, also asked the participants about their general feelings of joy over time - how loved they felt, their connection to society, how much they trusted the world and whether they thought they were becoming the person they wanted to be.
"Those things became a very dynamic picture of happiness, rather than just positive emotions."
She found that physical actions such as celebrating by jumping up and down, high-fiving or rushing over to a friend to share good news actively boosted feelings of happiness, as did self-focused actions, including congratulating yourself.
Dr Chadwick graduated as a doctor of philosophy in psychology at Tuesday's graduation ceremony.