Based on our analysis of Illinois public school report card data released Oct. 30 by the Illinois State Board of Education, we can see plainly that many of the high schools in the state with the highest proportion of students coming from low-income households have the lowest ACT scores.
That’s a very clear correlation, too. However, as my freshman science teacher, Frank Wing, pointed out about 30 years ago, correlation doesn’t imply causation. Just because when low-income rates go up, ACT scores go down, doesn’t mean low income causes low ACT scores.
I have shared this example Mr Wing taught me with every group of students I have ever taught. Consider the clear and obvious relationship between drowning deaths and ice cream sales. The fact in the stats is that as ice cream sales go up, drowning deaths also tend to go up.
We would never think, though, that ice cream causes drowning! What’s going on here — the fact that ice cream sales increase during the summer months, which is when we also spend more time in the water, and if we spend more time in the water, we have a greater chance of drowning — is the same as what’s happening with the low-income rates and ACT score correlation. High school kids from low-income families tend to go to college at lower rates than those who come from high-income families. Money is a problem for low-income students when it comes to deciding whether to go to college or get a job at K-Mart or Wal-Mart after high school.
Because a higher proportion of students are not as set on going to college in low-income schools, compared to high-income schools, the motivation to perform well on college tests, like the ACT, will decrease at low-income schools. If teenagers are less motivated, their performance will definitely suffer.
So, in the drowning example, hot weather was the external variable that could easily explain why ice cream sales and drowning deaths are correlated. With the low-income level and ACT scores, the external variable is the tendency to go to college. Low income may cause a reduction in the likelihood of going to college, but it is reflected in the ACT scores of students at the school.
Across the state, 20 percent of schools reported an average ACT Composite score of 21.6 or higher. Low-income percentages were greater than 44.05 percent of the students at about 30 percent of the high schools in the state. Let’s see what schools had an average ACT Composite score in the top 20 percent while still having a low-income rate in the bottom 30 percent of the state. Trust me, this is going to be a really small number.
Our snapshot can be viewed for yourself at http://irc.schoolsnapshots.org/sch_zoom.pl?q=1011:1036:1012:1013:1014:1015. Try sorting the report by ACT Composite scores. You will notice the pink tabs are at the top in both that column, because you sorted by that column, as well as in the Low-Income % column, because the two columns have a strong correlation.
What this data analysis also shows is that it’s completely within the realm of possibility for a school to buck the trend. Jones College Prep in Chicago, with an average ACT composite score of 24.6, has a low-income rate of 54.9 percent. Lane Tech, also in Chicago, has a low-income rate even higher, 62.5 percent, but still managed to record ACT scores in the top 10 percent of the state — and not just for the composite score, either. They also recorded scores in the top 10 percent of the state on the four subtests: reading, English, math, and science.
If we now drop down to the second decile in the ACT Composite column, we find just a few more schools that achieved high on the ACT despite a high low-income rate at the school: Lincoln Park High School in Chicago, Carbondale Community, and Lindblom Math & Science Academy High School in Chicago turned in ACT composite scores in the top 20 percent of the state and had low-income rates of 57.2, 45.6, and 75.6 percent, respectively.
Yes, we can all wish schools like these five were more the rule than the exception. Or we can pray to end poverty in our communities. But neither of these strategies will make it so. The two public high schools with the highest ACT Composite average, by the way, Northside College Preparatory High School and Payton College Preparatory High School, both in Chicago, have low-income rates of 34.8 and 33.4 percent, respectively, placing both schools just below the median rate across the state of 32.15 percent.
