Prince William, Prince Harry, Meghan Markle, Kate Middleton
Meghan Markle and Prince Harry inspired Prince William and Kate Middleton to be more touchy-feely. Pictured: Prince William, Prince Harry, Markle and Middleton arrive at Westminster Abbey to attend a service to mark the centenary of the Armistice in central London on Nov. 11, 2018. Getty Images/Paul Grover

Prince Harry and Meghan Markle may have inspired Prince William and Kate Middleton to be more tactile in public.

The royals are usually discouraged grom from showing PDA. In fact, the Queen and Prince Philip have never been seen holding hands in public the way the younger royals do.

On the other hand, the Duke and Duchess of Sussex have been very physical wherever they go. Prince Harry and Markle are often photographed holding hands or touching each other in some way. According to body language expert Judi James, it seemed that the Duke and Duchess of Cambridge are following them and are becoming less concerned with the rules.

"It's unusual to see William taking the lead in terms of public touch rituals with Kate, but on Remembrance Sunday he performed this back-touch ritual, even splaying his thumb out to signal a rather protective form of affection," James told Express.

"These small touches appear to have had an effect on the couple’s other body language signals," she continued. "Now that they are less obsessed with keeping to their more formal, non-tactile 'rules' they tend to look happier and more relaxed together too."

James believed that Prince Harry and Markle have something to do with Prince William and Middleton's behavior. According to her, they are typically taking cues from each other.

The Duke and Duchess of Sussex's tactile behavior "had a profound 'echo' on William and Kate's rituals." Prince Harry and Markle influenced Prince William and Middleton to "rekindle' their romance.

While the fab four have become more similar in terms of showing PDAs, they still behave differently when it comes to attending events. According to Camilla Tominey, Prince Harry and Markle have a "sprinkling of dust" that Prince William and Middleton lack.

"When we cover a job with Prince Harry, he is the event," Tominey explained. "If Harry's coming, something will happen, he'll engage with someone."

On the other hand, the Duke and Duchess of Cambridge are more introvert and shy. "They’re not that outgoing and often they don't make the buzz Meghan and Harry might, simply because they're just a bit more out there and more extroverted."

Tominey noted that their differences will be prominent when they split. Prince William and Prince Harry are reportedly considering a formal division now that they both have a growing family.