The umbrella term Pacific Islander or Polynesian has been criticised as degrading and insensitive.
Researcher Seini Taufa, who is a New Zealand-born Tongan, said the names were not indigenous terms and were insulting.
Taufa is research lead for Moana Research and Senior Pacific Advisor for the Growing up in New Zealand Longitudinal Study.
She has given evidence to the Royal Commission into Abuse in Care's Pacific inquiry being held in South Auckland.
Taufa quoted author, Albert Wendt.
''I am called a Pacific Islander when I arrive at Auckland Airport. Elsewhere I am Samoan.''
Taufa said lumping everyone together robbed people of their true identity.
''We did not name ourselves Pacific Islanders, we did not name ourselves Polynesian. These are terms that were constructed by palagi within a colonial context.''
She said preconceived ideas around being called a Pacific Islander or Polynesian influenced the way Pacific people self identify.
''While the umbrella term Pacific is useful when making global comparisons, it's futile when applied to actual people and groups of people who consider themselves not Pacific or Polynesian, but Samoan, Tongans, Fijians, Cook Islanders and so on.''
Taufa said, in a New Zealand context, Pacific people have been marked for as long as they have settled in Aotearoa whereby the Pacific embodiment is interpreted differently from context to context.
''On the rugby field and among the All Blacks, Pacific male bodies are celebrated. In a crime and punishment context, Pacific male bodies are associated with racist discourses of violence, rape, gangs, fear and danger.''
''Pacific people thus construct their identities and live their lives at the intersection of positive histories, language and culture and negative and stereotypical ideas and beliefs produced by the dominant group,'' she said.
Taufa said many abuse survivors experienced racism and discrimination first hand.
One young man asked about his ethnic background responded with Samoan, but was told by someone in authority that he wasn't, as he was born in New Zealand.
''As a young boy who relates being Samoan to Christianity, to family and to his mother, he is forced to adopt an identity that doesn't belong to him - a New Zealander - and, with it, the trauma of what he was exposed to in state care as a New Zealander.''
She said it spoke to the power held by a dominant group.
''To label another with little consideration of the detrimental nature of such actions.''
Taufa said the importance of ones ethnicity should never be doubted.
''I hope that it raises questions amongst those in the system to be more cautious of how they record, how they document and the fact that it can and has, through our survivor voices, had an impact on their well being.''
Taufa said there were inadequacies of ethnic classification and data collection in New Zealand, both past and present.