In years to come, future generations may look back on 20th- and 21st-century schools and wonder where our mania for grouping children by age came from. Either that, or workplaces could evolve to be rigidly divided according to employees' year of birth.
Introducing an #edchat on whether students learn best alongside peers of their own age or whether they should instead be taught by ability, @tomwhitby asked: "If grouping kids by age is only necessary for record keeping and not learning, why not consider alternatives more in line with learning?"
But children define themselves by their age, according to @andrewf98, who said: "Age groups are important, as are gender groups and culture groups. Grouping helps students understand who they are and what they face." Distinctions based on age continue long after school, he added.
Age is more than just a number, said @kafkat. It is an indication of what stage children are at. "Solely age grouping - no," she said. "But to a simplified point, age is brain-development grouping."
Just because children are of a similar age does not mean they will function well in the same class, according to @saratruebridge. She was asked to teach a 3rd-grade class (ages 8-9) where half the pupils had been identified as gifted and half had individual education plans (IEPs) for special educational needs.
"Awesome experience," she said. "IEP students thrived and demonstrated being gifted! Many `gifted' students demonstrated socialemotional issues and stress."
This prompted @_debboliver to question why only students with special educational needs should have tailored programmes. "Shouldn't all students have an IEP for individualised learning?" she asked. That would truly mean the end of age-based grouping.
@tomwhitby is not convinced that age-related teaching has a future. "People in real life including kids are not grouped by age, and things are just fine," he said.
But what if this point misses what is right in front of us? Maybe other factors mean that employers - such as internet start-ups with youthful workforces - already informally group staff by age. Age-related segregation could be the future, rather than something to be confined to history.
Keep up to date with the latest education chat online by following @tes on Twitter