At the age of 24, Mr Shaun Lim's social circle consists mainly of his friends from university and junior college.
The final-year law student from the National University of Singapore (NUS) graduated from top schools, including Raffles Institution and Nanyang Primary School.
"Most of the people in law have similar backgrounds. I have a classmate from polytechnic but she's an exception," says Mr Lim.
His experience reflects a study finding that the type of school influences the type of friends you make, that people who come from "elite" schools tend to mix with their own kind.
Indeed, Mr Lim's first extended experience of people from other backgrounds came when he undertook that rite of passage, national service, where he was posted to lead an infantry unit.
"It was quite a different experience from basic military training and Specialist Cadet School. There were the Hokkien-speaking guys, it was almost like (local comedy) Army Daze but a lot less funny," he says.
But beyond the army, hardly any opportunity arose for Mr Lim - whose father is between jobs and mother is a bank manager - to make friends with people from other types of schools.
He took part in a few inter-school camps as part of the National Police Cadet Corps when he was younger.
"We were put in groups of people from different schools from our geographical area, but there was still a tendency to mingle with friends from your own school," he says.
A week of camp is also not enough to develop close friendships, he adds. "The ties are just not as strong as those you form from studying together for a year or more."
Academics say it is natural that people form stronger connections with others they meet in their formative schooling years.
Education policy expert Jason Tan says: "By default, and by no one's fault, the school trajectory you take narrows the kind of people you see every day."
He adds: "Schools are actively doing their part to encourage students to be aware of the larger society, through subjects like social studies, community service, inter-school activities and overseas trips.
"But some of these activities are periodic and of short duration, so the difficulty is in ensuring they have longer-lasting impact beyond their completion."
REACHING OUT BEYOND FRIEND CIRCLE
But Mr Lim - an only child who lives with his family in a Bedok condominium - does not live in a complete bubble.
He has spent much of his time as a volunteer at the State Courts, helping train his juniors and building a programme where law students help the public understand processes like filing claims and applying for court orders.
For his efforts, he won the Pro Bono Leadership Award from NUS and the Outstanding Court Volunteer Award in the student category last year.
Since 2014, he has also been helping out with weekly Meet-the-People Sessions (MPS) in Buona Vista.
"I do try to be mindful that people don't always come from similar backgrounds. As an MPS volunteer, I do have a sense of the circumstances that less privileged families go through," says Mr Lim.
He adds: "A classless society is not possible, but those from less well-off backgrounds must feel that social mobility is possible, that they have enough opportunities to move up."