Table 27. Median age and age distribution of doctorate recipients, by broad field of study, sex, citizenship status, ethnicity, and race: 2015
(Percent distribution)

Broad field of study and demographic characteristic	Median age at doctorate (years)^a	All ages	25 and under	26–30	31–35	36–40	41–45	Over 45
All fields	31.6	100.0	0.7	43.8	30.6	11.6	5.3	8.0
Life sciences^b	30.9	100.0	0.6	49.7	29.6	9.8	4.1	6.2
Physical sciences and earth sciences	29.6	100.0	1.1	65.4	24.7	5.5	1.7	1.5
Mathematics and computer sciences	30.3	100.0	1.7	55.6	28.5	7.5	2.9	3.9
Psychology and social sciences	32.3	100.0	0.4	36.2	35.6	13.5	5.9	8.4
Engineering	30.0	100.0	1.3	60.0	27.2	6.8	2.1	2.6
Education	38.6	100.0	D	11.8	26.9	20.8	D	25.7
Humanities and arts	34.2	100.0	D	21.5	41.1	19.2	D	10.4
Other^c	34.7	100.0	0.3	24.3	32.9	17.5	9.4	15.6
Sex
Male	31.3	100.0	0.8	45.8	31.1	11.5	4.8	6.1
Female	31.9	100.0	0.6	41.4	30.1	11.8	5.9	10.2
Citizenship status
U.S. citizen or permanent resident	32.0	100.0	0.6	41.4	28.9	12.1	6.3	10.7
Temporary visa holder	31.0	100.0	1.0	48.9	34.5	10.5	3.2	2.0
Ethnicity and race (U.S. citizens and permanent residents)
Hispanic or Latino	32.6	100.0	0.4	36.7	31.7	14.2	7.2	9.8
Not Hispanic or Latino
American Indian or Alaska Native	37.2	100.0	0.0	17.1	28.7	14.0	14.0	26.4
Asian	31.3	100.0	0.7	45.6	29.1	13.5	5.8	5.2
Black or African American	35.7	100.0	D	24.9	25.9	14.4	D	22.3
White	31.8	100.0	0.6	43.0	28.9	11.5	5.7	10.3
More than one race	31.4	100.0	D	44.8	29.7	10.8	D	7.8
Other race or race not reported	32.7	100.0	0.9	36.7	30.7	17.2	3.7	10.7
Ethnicity not reported	32.3	100.0	0.8	39.7	26.2	13.6	5.0	14.7

Table 27. Median age and age distribution of doctorate recipients, by broad field of study, sex, citizenship status, ethnicity, and race: 2015(Percent distribution)