James Middleton is throwing his support for his big sister Kate Middleton. The youngest sibling of the Duchess of Cambridge is also promoting her latest initiative, which he doesn't usually do on social media. 

But on Instagram, James shared and promoted a link to Kate's "5 Big Questions on the Under Fives" survey. He urged his followers to spare five minutes to answer and join in the conversation about early childhood. 

James' social media is often filled with dog posts but he made a rare gesture of promoting his sister's newest project for The Royal Foundation. He even said that he is giving his huge support to his "wonderful sister."  The youngest Middleton sibling also said that while he doesn't have any kids yet, his sister's survey will help bring a brighter future for the next generation.  

The 32-year-old entrepreneur also posted a photo of himself as a child holding his grandparents' dog, a Bulldog named Gibson. Kate recently shared in a podcast interview Happy Mum Happy Baby that she and her siblings, Pippa and James, had many happy memories with their grandparents during their childhood. 

Kate shared that she had an amazing grandmother who spent time playing with her and her siblings. They did arts of crafts, gardening and lots of cooking in the kitchen. 

The duchess said that she's also instilling the same experiences in her own kids, Prince George, Princess Charlotte and Prince Louis. She added that it's these moments together that matter to the children's healthy physical and mental development most, as they have quality relationships with the people around them.

Meanwhile, Kate's mom Carole Middleton also publicly showed her support for her royal daughter. Using the social media account of her business, Party Pieces, Carole tweeted and enjoined the followers to take Kate's child development survey. 

The Duchess of Cambridge unveiled "5 Big Questions on the Under Fives" in January and has since been touring the U.K. to gather responses from parents, teachers, child minders, experts, charities and carers. 

Kate said that visiting as many communities as possible is helping her understand society's views and concepts in raising the next generation. Over 200,000 have apparently completed the short survey, which is but the first part of Kate's initiative. 

The royal hopes that early childhood development will also be an important part of conversations as much as other issues and advocacies. The duchess believes that everyone's experiences as kids bring a huge impact in adulthood.