A child psychologist says Tom Phillips' three children will be vulnerable and susceptible to anxiety after being isolated for three years.
Phillips and his three children, Jayda, 11, Maverick, 9, and Ember, 8, were seen on farmland near Marokopa last week for the first time since they went missing in December 2021.
Senior clinical psychologist Dr Sarah Watson, of Totally Psyched in Auckland, said given the children's ages and their disappearance from society, it might mean they are now afraid of any change to their situation which may trigger anxiety.
"By this stage because it's been so long, I imagine that the idea of integrating for them outside of what they're currently used to could be really terrifying.
"And also losing that one person potentially if that were going to happen, that has been their primary attachment figure, could be an incredible wrench of their sense of security and stability."
She said while the rest of the country might view the situation and what Phillips had done as negative, the children might not.
"You know when we talk about Stockholm syndrome - it's because we adapt and these kids will have needed to adapt with their dad."
The family were spotted by two teenage pig hunters west of Coutts Rd, near Marokopa last Thursday night.
One of the teenagers took a video of the group, who were wearing camouflage gear and backpacks and were walking in single file with Phillips at the front carrying a gun.
Police have confirmed it as the first credible sighting of the children since they were last seen in December 2021.
Watson said children were at a pivotal developmental age and their isolation from society would have a significant impact on that.
She said without knowing what the conditions and environment was like with their father, it was hard to know what the effects of their isolation would be.
"But certainly in terms of transitioning back into what may likely feel like a completely different world for them, coming back into I guess mainstream society - they've been out of school - so that's a huge adjustment for young people."
Assuming the children were found and returned to everyday life including schooling, which presented social relationships with peers, Watson said the effects would be significant.
"At present they've got each other which is great, but on the other hand we don't know whether they are actually socialising with other children and whether that's going to be something that's a challenge when things do change for them in the future."
She said children between the ages of eight and 12 were beginning to develop autonomy but being isolated meant the Phillips' children were prevented from developing crucial social and emotional skills.
"When you've got a limited environment there's limited things that you're actually able to demonstrate those new skills with and understanding, so if you then transition into a whole wider environment of a social, emotional and larger world, then that's a huge amount to try and cope with."
Watson said the longer the children were away from their peers, the more challenging it would be for them to form relationships, particularly for Jayda.
"When a child is 11 things change and it becomes more around identity formation... and that is very much around 'Who am I in the context of my peers?', people the same age."
She said it was normal developmentally for young children, especially girls who tended to be more sociable and wanted to please and be agreeable, that they would be moving from their parents as the centre of their world to their peers.
Watson said it could only be speculated what exposure Jayda may have had to her peers in the past three years.
"...it certainly could make it incredibly challenging for her to form relationships the longer she's away from them.
"Also being able to figure out who you are in response to other people your same age."
Watson said if the children had experienced any trauma it would add to their challenge of reintegrating.
She said there would also be an impact on their ability to learn, and their bond with mother, Cat.
Cat spoke on Wednesday to Mata Reports of her heartbreak at her children being kept from her and said they deserved better.
Watson said when children were separated from a significant attachment figure such as a mother or father, that disruption can be really confusing for them.
"You add on top of that the parents maybe have their own ideas around what has happened and then explain those to the children in their own perspective, once those children are reunited with the other parent - who may have a different perspective completely on what happened - then it can leave children feeling really very confused."
It could also make them question who they should believe.
"And who do I align myself with when this person has cared for me so deeply but it's against the laws of our country?
"I can just imagine huge amounts of confusion and likely distress for the kids."