STORRS, Conn. — Spencer Mulligan knew his family could pay for his college education, even without loans or grants. So when the University of Connecticut offered a merit award of $20,000 over four years, he saw it as a bonus.

As a discount on in-state tuition, it brought the cost well below half of what his family might have paid at his other top choices, Penn State or the University of Vermont.

“My dad was kind of split because he didn’t want to push me into going to a school because of financial reasons,” said Mulligan, a 21-year-old computer science student from Darien, one of the nation’s wealthiest communities. “Without financial reasons I might have gone to Penn State, but on the other hand he was like, ‘If you go to UConn, it will save us a bunch of money.’

“That means now I can pressure him into getting me stuff,” he joked.

Financial aid, traditionally a lifeline for poorer students at public colleges, is increasingly being used to attract students from more affluent families. In competition with private schools and other public institutions, the state schools are using the money to lure the most qualified students, raise average test scores and entice students from high-income families who can pay the rest of the full sticker price.

Critics say that by devoting aid to students who don’t need it, state schools are punishing the poor, making it harder for them to attend college when the gap between tuition costs and affordability is only growing.

“The reality is that for poor families, it’s a question of whether the kids go to college at all. For the better-off family, it’s a question of which college,” said Harold Levy, director of the Jack Kent Cooke Foundation, which provides need-based scholarships. “It’s a tragic waste of talent. It alters the lives of students.”

Other state schools have moved resources even more aggressively to merit aid. A review this year by Stephen Burd, an analyst with the think tank New America, found 28 percent of public colleges in 2014-2015 spent at least half of their aid dollars on students without financial need.

It’s a shift that has helped state universities cope with declines in state funding for higher education; the awards bring in students whose families can pay close to full tuition.

At UConn, as at many other flagship state schools, out-of-state students have benefited most from the increase in merit aid, according to a 2014 legislative report. The school costs $25,802 annually for residents and $47,344 for those out of state.

State universities are adopting an approach used by private schools. A report from the University of Pennsylvania’s Institute for Research on Higher Education this year said states’ provision of need-based financial aid barely changed from 1996 to 2012, while state aid for high-income students rose more than 450 percent.

At UConn, which has been climbing U.S News & World Report rankings, officials have vigorously defended merit awards when pressed by state lawmakers. Scholarships offered to top students, are critical to the university’s success, they say.

Jeslyn Lamonte, 19, of Vernon, Connecticut, is planning to transfer to UConn next year after two years of smaller payments at Manchester Community College.

“It came down to that I didn’t want all the student loans,” Lamonte said.