With about 20 fidgeting first-graders seated on the carpet in front of her, Kimball Elementary teacher Jacqueline Martinez took an informal poll before reading time.

Are girls allowed to play with Lego blocks, she asked. Can boys like the color purple? Both questions drew a unanimous thumbs up from her students. But their opinions were a bit more mixed when Martinez asked if dads could cook in the kitchen, or if moms should mow the lawn.

“Some people think boys should only do some things, and girls should only do other things,” Martinez told the class.

Over the past month, teachers in a dozen elementary schools in Seattle have piloted similar lessons on gender and self identity that are designed to fulfill new state standards on health education. The standards, adopted last year, require schools to teach students as young as kindergarten about the different ways to express gender, while fifth-graders learn about ways to show respect for all people and how to identify a trusted adult to ask questions about gender identity and sexual orientation.

In Seattle Public Schools, a task force of parents and teachers spent about a year developing the lessons and selecting the books for specific grades, said Lisa Love, the district’s health-education manager. She said individual teachers and schools also have increasingly requested age-appropriate tools to help guide conversations with students about gender expression and gender roles.