About half of unionized teachers at elementary and middle schools believe academic performance of their students is mirrored in the growing differences in their parents' incomes, according to a survey by Kyodo News.

Twelve percent of teachers polled said they "strongly believe" that widening gaps between students who do well and those who don't stems from growing differences in parental incomes, while a further 36 percent said they "partly believe" this is the case.

The survey, conducted earlier this month, covered 126 teachers who said they were going to attend a three-day annual meeting of the Japan Teachers Union in Mie Prefecture that started Saturday. The union has about 310,000 members.

Asked to describe differences in parental income over the past decade, 29 percent said they "vividly perceive" such gaps have expanded, with another 48 percent saying they "mildly" perceive such gaps.

Of the teachers who said such gaps have grown, 70 percent said many parents do not spend the necessary time helping children at home to make up for insufficiencies in knowledge.

In the poll, in which respondents were allowed to select more than one answer from several options, 32 percent said some parents cannot even pay for their children's school lunches.

Twenty-four percent said many parents are not seriously interested in improving their children's academic abilities.

In addition, 18 percent said parents are reluctant to spend money on supplementary education, such as cram schools or extra reference books for their children.

Asked to explain declines in their students' academic performance, many teachers said parents have apparently become unwilling to make financial sacrifices to help their children improve.

Asked if their schools have taken any measures to compensate for poor performances by their students, only 3 percent said adequate steps have been taken, and 79 percent said such measures have been insufficient.