"Mobile handsets are now considered a life partner for most, holding valuable information and helping people to carry out their day-to-day lives through email, calendar, weather apps and social networking," she said.
Another personality type, the "constantly online professional", is contactable 24 hours a day.
To them, their smartphone is a business partner, mailbox and organiser all in one package.
More than two-thirds of these people check their emails once a day, and are regular users of gaming apps.
The "fear of missing out" user is regarded as a social enthusiast who uses their smartphone to access their friends' activities.
They are frequent users of social media and are early adapters to new apps.
Then there is the "social creator" who like to voice their opinion first to avoid being seen as followers.
They frequently comment on online review and current affair sites, forums and blogs, and have a selection of news apps which they access up to four times a week.
The study of 1000 Australians for Optus was completed in March.
- AAP