Table 3.
Included studies language domain and calculated effect sizes
| Authors | N | Age | Comparison | Subdomain(s) | Instrument(s) + Type(s) | Results | Effect sizes |
|---|---|---|---|---|---|---|---|
| Zampini et al, 2018 | 15 XXX /XXY | 24 months | Control group | Vocabulary size | CDI (P) | XXX/XXY < controls | d = 2.18*** |
| Verbal productions | Structured‐play session (O) | XXX/XXY < controls | d range = .99‐1.44*** | ||||
| Number of Utterances | XXX/XXY < controls | d range = 1.76‐2.08*** | |||||
| Pointing gestures | XXX/XXY > controls | d = 1.03*** | |||||
| Haka‐Ikse et al, 1978 | 25 XXY | 36‐72 months | Normed scores | Language difficulties | YDS (P) | >50% | N/A |
| Ross et al, 2008 | 47 XXY |
4‐9; 11 years 10‐17; 8 years |
Normed scores | Complex levels of language processing | TLC‐E (C) |
XXY < controls; Older boys < younger boys |
d = 1.45*** |
| Expressive vocabulary | EOWPVT (C) | n.s. | |||||
| Receptive vocabulary | ROWPVT (C) | n.s. | |||||
| Semantic fluency | DKEFs (C) | n.s. | |||||
| Phonetic fluency | n.s. | ||||||
| Phonological processing | CTOPP (C) | n.s. | |||||
| Ross et al, 2009 |
93 XXY 21 XYY |
4‐18 years | Control group | Receptive vocabulary | ROWPVT (C) | XYY < XXY < controls |
d xxy = 1.15*** d xyy = 1.85*** |
| Complex levels of language processing | TLC‐E (C) | XXY = XYY < controls |
d xxy = 1.63*** d xyy = 1.33*** |
||||
| Expressive vocabulary | EOWPVT (C) | XXY = XYY < controls |
d xxy = .96*** d xyy = 1.17*** |
||||
| Phonetic fluency | DKEFs (C) | XXY = XYY < controls |
d xxy = .97*** d xyy = 1.08*** |
||||
| Phonological processing | CTOPP (C) | Inconclusive results | |||||
| Semantic fluency | DKEFs (C) | n.s. | |||||
| Bishop et al, 2011 |
58 XXX 19 XXY 58 XYY |
4‐17 years | Control group | Structural and pragmatic difficulties | CCC (P) |
XXX 44%‐68% XXY 50% XYY 38%‐85% |
N/A |
Note: *** High clinical significance; ** Moderate clinical significance; * Low clinical significance; N/A, not applicable; n.s., no significant differences.
Abbreviations: C, Performance Task Child; CCC, Children's Communication Checklist; CDI, MacArthur Communicative Development Inventories; CTOPP, Comprehensive Test of Phonological Processing; DKEFs, Delis‐Kaplin Executive Function system; EOWPVT, Expressive One‐Word Picture Vocabulary Test; O, Observation; P, Parent Report; ROWPVT, Receptive One Word Picture Vocabulary Test; TLC‐EL, Test of Language Competence—Expanded Edition; YDS, Yale Developmental Schedules.