But when the local school tested Isaac in kindergarten for the gifted and talented program, he didn't qualify.
And Houston's enrollment statistics indicate that Hispanic students like Isaac and African-American students would more likely be identified as gifted if they were white or Asian. That's a trend across the country.
Aguilar is stretched thin between his job building servers for a software company and finishing his college degree in statistics. So, getting to spend time alone with Isaac is really special, but finding time to get involved with his son's school is difficult. Aguilar knows the gifted and talented program exists at Herrera Elementary, though he wasn't aware the school was testing Isaac.
Donna Ford, at Vanderbilt University, thinks that put Isaac at a disadvantage. She's been researching gifted education for decades, and when it comes to Houston's program she says, "I think it's a clear case of segregation, gifted education being segregated by race and income."
Houston school leaders asked Ford to take a close look at their enrollment in the program, and she gave it a failing grade. "Racial bias has to be operating, inequities are rampant. Discrimination does exist whether intentional or unintentional," she told the school board in May of this year.
Ford found that both Hispanic and black students are underrepresented in gifted programs and that black students are missing out the most. She also found that about half the seats in those programs go to higher-income students, even though the majority of the district is poor.
Ford calls it "a waste of a huge number of students' gifts and talents."
Ford says Houston's entire process is laced with problems. She's seen this in other districts and has ideas on how to improve it, starting with the test.
Houston uses an exam that some educators consider culturally biased, so it may fail to identify a student like Isaac as gifted.
Also, teacher recommendations carry a lot of weight, but can be subjective.
And Ford worries that because the whole selection process is point-based, some families can strategize to get their kids in the program. "Knowing the system, working the system, using that social capital, it does advantage you," she says.
Parents in the know can find tutorials online. Some even spend $150 for test materials. Meanwhile, other families have no idea the gifted program even exists.
And Adam Stephens says he wants to change that. He's the person at the Houston Independent School District in charge of advanced academics, and says there's no sacred cows when it comes to making changes for the better.
"We're looking at the testing that we use," Stephens says. "We're looking at how we identify students at the campuses, and if it feels like it's really going to allow us to really meet the needs of students in HISD, then it's something that we're committed to moving forward."
And as for Isaac, the district says it will test him for the gifted program again this fall.
Read more about gifted students from NPR Ed's lead blogger, Anya Kamenetz.