When music teacher Aaron Low noticed that his two sons were forming a clique, excluding their two sisters, he started rostering a different kind of family outing.
Every month, the 38-year-old would take each of his four children out in turn. However, in July, this dad-and-me time morphed into party-of-three affairs.
"I deliberately made a schedule so every one of them could go out in different pairs. I have a roster kept in my phone," says Mr Low, whose wife Grace is expecting their fifth child, a girl.
He appreciates that his sons Gabriel, 10, and Gaius, eight, are bonding over interests such as basketball, badminton and playing the ukulele. But he also wants his sons to "relate more" to their two sisters, aged nine and four, so it is "not just boys and girls".
Cliques among siblings are "not particularly significant in sociological terms, especially as there have been far fewer large families... over the past 50 years", says sociologist Stella R.
Quah from the Duke-NUS Graduate Medical School, who adds that parents cannot do anything about siblings forming cliques and that they are not to blame.
"The number of children has diminished and therefore any problems between siblings are less significant now. It's mostly families with two children now in Singapore."
Still, they are not uncommon, interviews with families by SundayLife! showed, and gender-based groupings are only one permutation.
Unlike Mr Low, most of the parents interviewed took a more hands-off approach to managing clique dynamics, intervening as a last resort, usually when fights and quarrels erupt.
Housewife Gaye Chan, 44, who has three girls, says: "I find that sometimes when we intervene too much, we lose that opportunity in which the children learn to manage conflict."
Counsellor Chang-Goh Song Eng, head of Reach Counselling, says: "As far as possible, parents generally do not need to step in, unless after careful observation over time, they notice behaviour that may be damaging to the child's development, for example, bullying among siblings."
With five children, including two sets of twins, manager Chew Chin Wee says cliques among his offspring, aged between six and eight, are "gender and age-related".
His three girls are able to talk about "things pertaining to primary school", whereas their brothers are still in kindergarten, says the 41-year-old.
He adds that he has not observed any strong affinities between his fraternal twin children - one pair of girls and one pair of boys - who have "very different" personalities.
Although his eldest daughter Koh-San, the only non-twin, says she sometimes watches television by herself, his wife, property agent Sabrina Goh, says cliquing is not particularly pronounced and that the siblings generally play together.
"They play cards and Lego together, for example, and invent their own games, sometimes playing their own musical chairs," says the 37-year-old.
The small age gaps contribute to a home environment akin to a "perpetual playground", adds Mr Chew.
Sibling order can be another factor in the formation of cliques. Megan Wong, Nanyang Primary School pupil and eldest of four children, 12, says she bonds more with next-in-line Elliot, seven, because he is "my first brother and I know him better. He's very loving".
Megan acknowledges that she and Elliot sometimes "gang up" against their five-year-old brother Regis, though they all "make up very fast" after fights involving various sibling combinations. Their youngest brother, 15-month-old Enzo, is not involved.
"Sometimes Regis might irritate Elliot and Elliot might hit back. They will go down the hallway to my room and I will join in," says Megan.
Their mother, nutritionist Sherlyn Quek says: "Most of the time we let them sort out their squabbles. I usually step in when Elliot and Regis wrestle. Elliot is very strong."
Family solidarity trumps domestic bickering, though: Megan and Regis are protective of Elliot, who has Down syndrome. Both of them get upset when people make remarks about Elliot, says
Ms Quek, 39, adding that she tells her children in such instances that they can educate others about the genetic condition.
She says that she and her husband treat Elliot the same in terms of discipline, adding that he has "brought the siblings closer, he's taught Megan and Regis empathy, patience and compassion".
Ms Chan has observed a natural fluidity in the way her three girls, aged nine, 13 and 16, relate to one another as they grow up.
Describing how forming cliques is linked to developmental stages, she says: "Currently, my two older ones are into their teenage years and I can see that they are closer.
"It has changed from two years ago, when the younger two were getting along better, after the youngest entered primary school and studied with the middle child."
Pre-school teacher Siti Radhiyah, 32, can attest to the evolving nature of some sibling cliques. Her youngest sibling, the only boy among five children, was born when she was 20.
As the eldest child helping to care for him, she says she was more like a guardian at that time and felt left out as her siblings were closer to one another.
This feeling of isolation evaporated over the years.
"The gap because of age tends to close when we get older as we tend to communicate more. After I got married and had other responsibilities, my siblings also played more of a role in caring for my brother," says Ms Siti, who is expecting her third child.
Amid the routine quarrels of childhood, parents sometimes reap one perhaps unexpected benefit of sibling cliques - problems tend to be shared within these charmed circles and sometimes they filter to parents on a need-to-know basis.
When Primary 5 pupil Elizabeth Kang bore the brunt of a minor bullying incident over a few weeks, she confided the matter to her clique buddy, brother Judah, nine. They are the eldest of four children in their family.
Elizabeth says: "My friend pinched my cheeks and took away my stationery, which she gave back at the end of the day."
Their father, school vice-principal Andrew Kang, 43, says: "When we asked the kids how they were doing at school, Judah told us about this first. The siblings would tell each other things first."
Mr Kang called the parents of the offending child, who apologised to Elizabeth.
"Elizabeth was happy that we found out in the end because we settled it for her," says mum Jessica Kang, 42, who is a teacher.
Sibling cliques can vary, motivated by shared interests, time spent together and myriad other factors.
Madam Haslinda Mohd Amin, 40, and Mr Erwan Abdul Kadir, 41, say, however, that there is no dominant clique among their nine children, aged two to 15.
But the four boys - the "IT department", their father quips - are interested in computers and the two eldest girls, Siti Nur Hawa, 14, and Siti Nur Hajar, 11, watch Korean dramas and sometimes sell loom bands and other handicraft at a flea market.
The younger children form cliques as the girls spend most of the week together in childcare, while the boys go for the same after-school student care programmes, their parents say.
Mr Erwan, a logistics coordinator, and Madam Haslinda, a billing clerk, express anxiety about their second child and eldest daughter, Hawa, feeling isolated in the hurly-burly of caring for a large family.
Their eldest, 15-year-old Muhammad Adam, received a lot of attention when he was younger on account of health problems he experienced at the time.
"Hawa is more independent and more outgoing than Adam," says Madam Haslinda, adding that her eldest son was less likely to feel isolated from his siblings, spending more time at home.
"(Hawa) became very independent, she juggled her studies and looking after the younger ones," says Mr Erwan.
He admits they have "never discussed" whether Hawa feels left out in front of her. "Normally I discuss it with my wife," he adds.
Hawa says she did not know her parents are so concerned about her.
"I'm really touched," she says.
This article was first published on Sept 07, 2014.
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