A government thinktank in South Korea has sparked anger after suggesting that girls start primary school a year earlier than boys because the measure could raise the country’s low birthrate.

A report by analysts at the Korea Institute of Public Finance said creating a one-year age gap between girls and boys at school would make them more attractive to each other by the time they reached marriageable age.

The claim is based on the idea that men are naturally attracted to younger women because men mature more slowly. Those women, in theory, would prefer to marry older men.

“Considering that the developmental level of men is slower than that of women, having females enter school one year earlier could potentially contribute to men and women finding each other more attractive when they reach the appropriate age for marriage,” the report on tackling the decline in the working population said.

It added: “If there is a willingness to marry, then a willingness to date can certainly be assumed. However, that does not necessarily lead to successful dating. To improve this, policies that could be included in this category are those that arrange meetups, improve social skills, and support self-development to boost one’s attractiveness to the opposite sex.”

The suggestion is one of several ideas put forward to address South Korea’s demographic situation.

Shin Gyeong-a, a sociology professor at Hallym University, told the Korea JoongAng Daily newspaper: “That such a report, without any screening, was published in a democratic country – by a state-run research institute that will evaluate measures to address low birthrates in the future, no less – is ridiculous.”

Lee Jae-myung, the leader of the main opposition party, described the report’s recommendations as “absurd”, adding: “We need to take fundamental and macro-level measures [against the low birthrate].”

The criticism continued online. One user of the Naver platform said: “Are they really looking at people, at children, as reproductive tools? Disgusting.”

The proposal was “worse than telling them not to have kids”, another wrote, while others complained that taxpayers’ money had been used to fund the report. “Instead, they should propose policies to create the right environment for raising children,” one user said.

In response to the criticism, the institute said the state-funded report contained the views of the individual authors and did not necessarily reflect its official view on government measures to raise the birthrate. The Guardian has approached the institute for comment.

South Korea’s birthrate of 0.72 children per woman is the lowest in the world. The rate is even lower in the capital, Seoul, where authorities have projected the population will fall to 7.9 million by 2052, from 9.4 million in 2022.

The trend has been blamed on the high cost of raising and educating children, and the lack of affordable housing, as well an expectation that women will devote themselves to bringing up families rather than balance work with family life.

Last month, the Seoul metropolitan government said it would offer up to 1m won (£775) to couples who have sterilisation procedures reversed. The national government, meanwhile, is reportedly considering raising its one-off financial incentives to have children up to £77,000.

This summer, 100 Filipino domestic helpers and childminders will arrive in South Korea as part of a pilot programme designed to ease the pressure on working women who fear they will have to leave their jobs if they have children.