Kate Middleton and Prince William, both 38, met at university and got engaged in 2010. They married just one year later, and the royal couple now have three children. What is their relationship like?
The expert added: “Lots of couples use mimicry when they first pair up and the conscious copying of your partner’s body language shows a desire to create the strongest bonds and to display your closeness to the rest of the world.
“This usually means one of the couple will tend to copy or mimic the other though, usually the one copied being the one with the stronger or more powerful personality.”
Kate and William aren’t the only royal couple to be seen doing this.
“Camilla and Charles are often seen standing or moving in similar ways but that is because Camilla tends to follow Charles’s lead when they appear in public,” said Judi.
She added: “William and Kate show signs of subconscious mirroring though, meaning it is a more natural trait for them to the point where they might not even be aware of it.
“It is what defines them as a couple, showing they will probably be in tune over big things like royal behaviour, brand and appearances and the way they bring up their children.
“It reflects in their similar personality traits, like competitiveness, and it also shows a certain even-balance when it comes to power and status in their relationship.”
The expert explained many couples also share this trait of mirroring one another.
Judi said: “Many couples share this trait of mirroring but for Kate and William it is more exceptional than normal.
“William was brought up as a royal and he served time in the forces.”
According to Judi, this should mean that the Duke’s signals should set him aside from his wife.
The expert said: “Both of those experiences should have made his body language very different to Kate’s.
“But there were signs of a sense of merging and subconscious compromise from their wedding day.
“Once Kate was part of the firm we saw William’s ‘royal wave’ becoming, like Kate’s, lower and less formal, while Kate adopted the ‘fig leaf’ pose with her hands clasped in front of her torso, that was a signature pose of her husband’s.”