“WHY CAN’T YOU SIT STILL?:” HYPERACTIVITY AND SCHOOLING OUTCOMES FOR CANADIAN BROTHERS AND SISTERSKelly Chen, Nicole Fortin, Philip Oreopoulos and Shelley Phipps

This research is being conducted as part of the Canadian Institute for Advanced Research (CIFAR) Programme on Social Interactions, Identity and Well-Being

We thank CIFAR for funding support and Heather Hobson of the Atlantic Research Data Centre for vetting our output

Motivation Young women now constitute the

majority of undergraduates on most Canadian campuses

Young women have caught up with and surpassed young men in terms of educational attainment In 2008, 36.5 percent of Canadian

women aged 25 to 29 had a university degree compared to 24.1 percent of young men (Drolet, 2011)

Research Questions What are the roots of this

phenomenon? Are gender differences in educational

outcomes apparent from the beginning?

If gender differences already evident for young children, why is this so?

Could a greater tendency to hyperactivity for boys be part of the story?

Conceptualizing “Educational Outcomes”

Test scores important, not the full story

Also important is the development of an identity as a student (Akerlof and Kranton, 2000; 2010) Attitudes toward school? Liking for school? Aspirations?

A role for hyperactivity? Children with ADHD have lower test

scores and are more likely to repeat a grade at school (Currie and Stabile, 2006)

Epidemiological literature clear that boys are more hyperactive than girls

More hyperactive children may find it harder to be the “ideal student;” to fit in nicely with the social environment of the classroom

They may find it harder to sit still and concentrate

They may get in trouble more, do less well, be less motivated

Hasn’t this always been true? Trend data on ADHD surprisingly limited, but some

evidence of increases in ADHD (Perrin et al., 2007) Norms/expectations of young school children may

have changed School environments less accepting of ‘boisterous’

behaviour (cuts to physical education, no ‘rough-housing’ on the playground)?

Serious work (reading) started younger? If so, long-standing gender differences in

hyperactivity levels may have become more problematic

*** not necessarily only clinical levels of hyperactivity that are important

Currie and Stabile, 2006 find parent reports of hyperactivity are associated with lower test scores well below clinical thresholds

Research Strategy Test for gender differences in test scores

plus parent assessments of over-all achievement and motivation for Canadian children aged 6 through 11

Use sibling difference models (to control for family background)

Include index of parent-reported hyperactive symptoms to test hypothesis that hyperactivity of boys helps explain gender differences

Data Statistics Canada National Longitudinal

Survey of Children and Youth, 1994 through 2006 (every two years)

Pool sibling pairs from all available cycles, 6 through 11 years, each pair randomly selected once

Parent (person most knowledgeable) provides all information used here (except math test scores)

Parent’s Assessment of Child’s Liking for School

Question: “With regard to how he/she feels about school, how often does he/she look forward to going to school?” Almost never, Rarely, Sometimes,

Often, Almost Always

How Often Does Child Look Forward to Going to School?

Boys Girls0

1020304050607080

3.5 1.64.4 2

12.97.3

18.7 15.3

60.5

73.9

Almost Never RarelySometimesOftenAlmost Always

Relative Liking for School of Brothers Compared to Sisters

Brother Likes School Less

Same Liking for School

Sister Likes School Less

0

10

20

30

40

50

60

32.3

55.2

12.5

Parent’s Assessment of Child’s Over-all School Performance

Question: “Based on your knowledge of his schoolwork, including his/her report cards, How is he doing overall?” Very poorly, poorly, Average, Well,

Very well

How Well is Child doing at School Overall?

Boys Girls0

10

20

30

40

50

60

4.1 2.3

25.419.2

31.3 28.3

39.2

50.3

Very Poorly or PoorlyAverageWellVery Well

Relative Over-all Success at School of Brothers Compared to Sisters

Brother Worse Same Sister Worse05

1015202530354045

38.741.9

19.4

Parental Expectations for Child’s Future Education

Question: “How far do you hope this child will go in school?” High School or Less Some Post-Secondary University

How far do you hope your child will go in school?

Boys Girls0

102030405060708090

7.4 5.6

24.2 21.3

68.4

84

High School or LessCollege, Trade, Some Post-secondaryUniversity

Relative Educational Expectations for Brothers Compared to Sisters

Brother Lower Same Sister Lower0

10

20

30

40

50

60

70

80

14

76.7

9.3

Hyperactivity Index “How often would say this child . . .”

“Can’t sit still or is restless?” “Is easily distracted, has trouble sticking to any

activity” “Can’t concentrate, can’t pay attention for long?” “Is impulsive, acts without thinking?” “Has difficulty waiting for his turn in games or groups? “Cannot settle to anything for more than a few

minutes” “ Is inattentive?”1= Never or not true; 2= Sometimes or somewhat true;

3= Often or very true

Construction of Score Add for all items Score ranges from 0 to 14, with high

score indicating highest level of hyperactivity

Mean for sample = 4 Children ‘on ritalin’ have mean score =

9.4

Boy Girl0

0.51

1.52

2.53

3.54

4.55 4.5

3.4

Hyperactivity Score. All 6 to 11 year-old Children.

Hyperactivity Scores for Brothers Compared to Sisters

Brother More Hyperactive Same Sister More Hyperactive0

10

20

30

40

50

60

7058.8

11.3

29.9

0.0

5.1

.15

.2K

erne

l Den

sity

0 5 10 15Hyperactivity Scores

Boy Girl

Distribution of Hyperactivity Scores

Estimation. Sibling Fixed Effects Models

To control for permanent, unobservable differences in family background

Yif = a + b1 BOYif + b2 HYPERif + λf + gXif + eif

Xif includes only variables that differ between siblings (e.g., age in months, ‘older child,’ health status and cycle)

Sibling Fixed Effects. Liking for School.

Boy -0.339***(0.027)

-0.331***(0.027)

-0.253***(0.027)

Hyperactivity Score

-0.051***(0.005)

+Covariates yes YesCycle Dummies included in all regressions. Covariates: Child’s Age in Months, Child Health, ‘Oldest Child’ Dummy

Sibling Fixed Effects. Success at School.

Boy -0.286***(0.025)

-0.274***(0.025)

-0.114***(0.024)

Hyperactivity Score

-0.110***(0.004)

+Covariates yes YesCycle Dummies included in all regressions. Covariates: Child’s Age in Months, Child Health, ‘Oldest Child’ Dummy

Sibling Fixed Effects. Parental Educational Hopes for Child.

Boy -0.061***(0.014)

-0.058***(0.014)

-0.028**(0.014)

Hyperactivity Score

-0.021***(0.003)

+Covariates yes YesCycle Dummies included in all regressions. Covariates: Child’s Age in Months, Child Health, ‘Oldest Child’ Dummy

Sensitivity Analyses Use parent report of ‘on ritalin’ rather than

hyperactivity score (1.1% of girls; 4.1% of boys) Use dummy indicator of ‘top decile’ of

hyperactivity score

Both highly statistically significant themselves but have less impact on estimated size of ‘boy’ coefficient than full score, suggesting it isn’t just ‘clinical’ hyperactivity than helps explain the gender difference

Size of ‘Boy’ Coefficient With and Without Controlling for ‘On Ritalin’

Liking School Good at School Parental Expectations

Boy -0.349***(0.025)

-0.343***(0.025)

-0.257***(0.023)

-0.242**

*(0.019)

-0.063**

*(0.012)

-0.057***(0.013)

On Ritalin

-0.272***(0.095)

-0.648**

*(0.086)

-0.234***(0.048)

These estimates are from sibling fixed effects models with covariates included.

With and Without Control for Top Decile Hyperactivity Score

Liking School Good at School Parental Expectations

Boy -0.325***(0.026)

-0.279***(0.026)

-0.251***(0.023)

-0.180**

*(0.023)

-0.050**

*(0.013)

-0.031***(0.013)

Top Decile Hyper Score

-0.345***(0.035)

-0.567**

*(0.031)

-0.130***(0.018)

These estimates are from sibling fixed effects models with covariates included.

Conclusions Using parent reports, boys like school less

(brothers like school less well than sisters); boys perform less well; boys are not expected to complete as high levels of education

Hyperactivity scores are negatively associated with these outcomes

When hyperactivity is included as a regressor in sibling fixed effects, the size of ‘boy’ coefficient falls