. 2017 Feb 3;47(4):1148–1165. doi: 10.1007/s10803-016-3013-0

Table 1.

Studies discussing planning in participants with autism spectrum disorders in comparison with typically developing control groups

Study by	Subjects M/F^a	Age range/ M(SD)	IQ range/ M(SD)	Group assignment ASD	Planning task	Measurement	E
Bölte et al. (2011)	ASD 35/21	14.2 (2.9)	IQ ≥ 70 PIQ: 99.2 (10.6)	Q: - SI: ADI-R, ADOS NSCA: clinical diagnosis CLAS: ICD-10	ToH	Total moves	g = −0.19
Bölte et al. (2011)	TD 23/35	14.6 (4.7)	PIQ: 103.5 (13.1)		ToH	Total moves	g = −0.19
In this study, unaffected siblings of the ASD group formed the comparison group (TD)
Boucher et al. (2005)	HFA 10/0	23.8 (7.8)	IQ ≥ 70 VIQ: 105.5 (20.2) PIQ: 90.3 (19.3)	Q: modified WADIC SI: - NSCA: clinical diagnosis CLAS: DSM-IV	Zoo Map test (with MRI)	Total score	g = 0.76
Boucher et al. (2005)	TD 10/0	24.2 (8.1)	VIQ: 104.4 (13.2) PIQ: 97.5 (16.9)		Zoo Map test (with MRI)	Total score	g = 0.76
Bramham et al. (2009)	ASD 38/7	32.8 (12.5)	IQ ≥ 70 FSIQ: 107 (16.4) VIQ: 106.5 (17.4) PIQ: 105.7 (17.7)	Q: - SI: ADI-R NSCA: clinical diagnosis CLAS: ICD-10	Zoo Map test	Accuracy Map 1	g = 0.19
Bramham et al. (2009)	TD 23/8	32.8 (9.0)	FSIQ: 109.8 (16.8) VIQ: 107.7 (15.8) PIQ: 111 (18.5)		Key Search test	Total score	g = 0.19
Brunsdon et al. (2015)	ASD 150/31	12.1–16.3/13.5 (0.7)	FSIQ: 49–128/ 90 (20.3)	Q: CAST SI: DAWBA (P), ADI-R, ADOS NSCA: clinical diagnosis CLAS: DSM-IV	Planning drawing task, part B (planning)	Planning error score	g = 0.43
Brunsdon et al. (2015)	TD 110/50	10.9–15.6/12.8 (1.1)	FSIQ: 56–142/ 101.9 (15.1)		Planning drawing task, part B (planning)	Planning error score	g = 0.43
Corbett et al. (2009)	ASD 17/1	7–12/ 9.4 (1.9)	IQ ≥ 70 FSIQ: 94.2 (17.8)	Q: - SI: ADI-R, ADOS NSCA: clinical diagnosis CLAS: DSM-IV-TR	SoC	Total perfect solutions	g = 0.91
Corbett et al. (2009)	TD 12/6	7–12/ 9.6 (1.8)	FSIQ: 112.2 (14.8)		SoC	Total perfect solutions	g = 0.91
Geurts et al. (2004)	HFA 41/0	6–13/ 9.4 (1.8)	IQ ≥ 80 FSIQ: 98.3 (18.4)	Q: - SI: ADI-R, DISC-IV (P) NSCA: - CLAS: DSM-IV, ICD-10	ToL	ToL score	g = 0.78
Geurts et al. (2004)	TD 41/0	6–13/ 9.1 (1.7)	FSIQ: 111.5 (18)	Q: - SI: ADI-R, DISC-IV (P) NSCA: - CLAS: DSM-IV, ICD-10	ToL	ToL score	g = 0.78
Geurts & Vissers (2012)	ASD 18/5	51–83/ 63.6 (7.5)	DART-IQ: 109.5 (10.3)	Q: SRS SI: - NSCA: clinical diagnosis CLAS: DSM-IV	ToL-Dx	Excess moves	g = -0.23
Geurts & Vissers (2012)	TD 18/5	51–83/ 63.7 (8.1)	DART-IQ: 109.8 (7.9)	Q: SRS SI: - NSCA: clinical diagnosis CLAS: DSM-IV	ToL-Dx	Excess moves	g = -0.23
Goldberg et al. (2005)	HFA 13/4	8–12/ 10.3 (1.8)	IQ ≥ 75 FSIQ: 96.5 (15.9)	Q: - SI: ADI-R, ADOS, ADOS-G NSCA: clinical diagnosis CLAS: DSM-IV	SoC	Total perfect solutions	g = 0.56
Goldberg et al. (2005)	TD 21/11	8–12/ 10.4 (1.5)	FSIQ: 112.6 (12.1)		SoC	Total perfect solutions	g = 0.56
Griebling et al. (2010)	HFA 35/2	8–45/ 19.1 (9.0)	FSIQ: 104 (15)	Q: - SI: ADI-R, ADOS NSCA: clinical diagnosis CLAS: -	ToH (with MRI)	Total moves	g = 0.95
Griebling et al. (2010)	TD 36/2	8–45/ 18.8 (9.0)	FSIQ: 104 (10)	Q: - SI: ADI-R, ADOS NSCA: clinical diagnosis CLAS: -	ToH (with MRI)	Total moves	g = 0.95
Hanson & Atance (2014)^b	ASD 22/3	3.2–8.3/ 5.9 (1.5)	FSIQ: 42–121/ 85.7 (21)	Q: CARS-II SI: - NSCA: clinical diagnosis CLAS: DSM-IV-TR	ToH	Highest level achieved	g = 0.09
Hanson & Atance (2014)^b	TD 22/3	3.1–5.9/ 4.9 (0.9)	FSIQ: 97–128/ 109.1 (8)	Q: CARS-II SI: - NSCA: clinical diagnosis CLAS: DSM-IV-TR	Truck loading	Highest level achieved	g = 0.09
Happé et al. (2006)	ASD 32/0	8–16/ 10.9 (2.4)	IQ ≥ 69 FSIQ: 99.7 (18.7) VIQ: 102.4 (18.1) PIQ: 96.6 (17.9)	Q: - SI: - NSCA: clinical diagnosis CLAS: DSM-IV	SoC	Total perfect solutions	g = 0.19
Happé et al. (2006)	TD 32/0	8–16/ 11.2 (2.0)	FSIQ: 106.8 (13.4) VIQ: 109.8 (12.2) PIQ: 101.7 (18.2)		SoC	Total perfect solutions	g = 0.19
Hill & Bird (2006)	AS 16/6	16–61/ 31.1 (13.1)	FSIQ: 80–135/ 110.5 (18.2)	Q: AQ SI: - NSCA: clinical diagnosis CLAS: DSM	Zoo Map test	Accuracy Map 1	g = 0.39
Hill & Bird (2006)	TD 14/8	18–64/ 33.5 (14.5)	FSIQ: 79–135/ 107.9 (14.9)	Q: AQ SI: - NSCA: clinical diagnosis CLAS: DSM	Key Search test	Total score	g = 0.39
Hughes et al. (1994)	ASD 30	8–19/ 13.2	Not assessed	Q: AQ SI: - NSCA: clinical diagnosis CLAS: DSM-III	SoC	Decision time	g = −0.43
Hughes et al. (1994)	TD 44	5–10/ 8.0	Not assessed	Q: AQ SI: - NSCA: clinical diagnosis CLAS: DSM-III	SoC	Decision time	g = −0.43
Joseph et al. (2005)	ASD 32/5	5.5–11.1/ 7.9 (1.8)	DAS FSIQ: 57–141/ 87.1 (19.9) DAS VIQ: 61–133/ 87 (19) DAS NVIQ: 49–153/ 91 (22)	Q: - SI: ADI-R, ADOS NSCA: clinical diagnosis CLAS: DSM-IV	Tower (NEPSY)	Total perfect solutions	g = 0.51
Joseph et al. (2005)	TD 24/7	5.1–11.7/ 8.3 (2.1)	DAS FSIQ: 61–117/ 89.8 (14.3) DAS VIQ: 64–122/ 88 (13) DAS NVIQ: 50–114/ 91 (17)		Tower (NEPSY)	Total perfect solutions	g = 0.51
Kaufmann et al. (2013)	AS 8/2	14.7 (5.0)	FSIQ: 102.3 (15.9) VIQ: 107.6 (13.2) PIQ: 95.8 (16.6)	Q: - SI: ADI-R, ADOS NSCA: clinical diagnosis CLAS: DSM-IV-TR	SoC (with MRI)	Total perfect solutions	g = −0.04
Kaufmann et al. (2013)	TD 8/2	13.8 (5.3)	FSIQ: 109.5 (6.4) VIQ: 114 (9.9) PIQ: 106 (10.6)		SoC (with MRI)	Total perfect solutions	g = −0.04
Keary et al. (2009)	ASD 29/3	8.8–45.7/ 9.8 (10.2)	IQ ≥ 70 75–135/ FSIQ: 102.9 (13.6) VIQ: 106.9 (15.6) PIQ: 97.8 (12.5)	Q: - SI: ADI-R, ADOS NSCA: clinical diagnosis CLAS: DSM-IV	ToH (with MRI)	Total moves	g = 0.93
Keary et al. (2009)	TD 31/3	9.2–43.9/ 18.6 (9.1)	86–121/ FSIQ: 104 (10.5) VIQ: 104.7 (10.4) PIQ: 102.6 (10)	Q: - SI: ADI-R, ADOS NSCA: clinical diagnosis CLAS: DSM-IV	ToH (with MRI)	Total moves	g = 0.93
Kimhi et al. (2014)	ASD 25/4	3–6/ 4.9 (0.9)	FSIQ: 103.5 (17.2)	Q: - SI: ADI-R NSCA: clinical diagnosis CLAS: DSM-IV-TR	ToL	Total perfect solutions	g = 0.58
Kimhi et al. (2014)	TD 26/4	3–6/ 4.6 (0.9)	FSIQ: 107.6 (14.1)	Q: - SI: ADI-R NSCA: clinical diagnosis CLAS: DSM-IV-TR	ToL	Total perfect solutions	g = 0.58
Landa & Goldberg (2005)	HFA 19	7.3–17.3/ 11.0 (2.9)	IQ ≥ 80 81–139/ FSIQ: 109.7 (15.8) VIQ: 113.5 (17.1) PIQ: 104.6 (13.5)	Q: - SI: ADI-R, ADOS (-G) NSCA: - CLAS: -	SoC	Total perfect solutions	g = 1.01
Landa & Goldberg (2005)	TD 19	7.2–17.2/ 11.0 (2.9)	90–138/ FSIQ: 113.4 (14.3) VIQ: 115.6 (15.8) PIQ: 108.5 (12.1)	Q: - SI: ADI-R, ADOS (-G) NSCA: - CLAS: -	SoC	Total perfect solutions	g = 1.01
Limoges et al. (2013)	ASD 16/1	16–27/ 21.7 (3.5)	FSIQ: 89–129/ 104.1 (11.3) VIQ: 103.2 (16.2) PIQ: 103.5 (13.1)	Q: - SI: ADI-R, ADOS NSCA: clinical diagnosis CLAS: DSM-IV	ToL (with EEG)	Total perfect solutions (%)	g = 0.64
Limoges et al. (2013)	TD 13/1	16–27/ 21.8 (4.1)	FSIQ: 92–124 112.3 (9.8) VIQ: 113 (9.6) PIQ: 112.1 (10.9)		ToL (with EEG)	Total perfect solutions (%)	g = 0.64
Lopez et al. (2005)	ASD 14/3	19–42/ 29.0	PIQ ≥ 70 FSIQ: 77 (15) VIQ: 73 (16) PIQ: 84.1 (12.2)	Q: GARS (P) SI: ADI- R, ADOS NSCA: clinical diagnosis CLAS: DSM-IV	Tower of California (D-KEFS)	Total constructed towers	g = 1.15
Lopez et al. (2005)	TD 11/6	18–45/ 29.0	FSIQ: 89 (13) VIQ: 92 (15) PIQ: 87.6 (11.7)		Tower of California (D-KEFS)	Total constructed towers	g = 1.15
Losh et al. (2009)	HFA 29/7	21.5 (5.5)	IQ ≥ 80 FSIQ: 101.2 (18.1)	Q: - SI: ADI- R, ADOS NSCA: clinical diagnosis CLAS: DSM-IV	ToH	Total moves	g = 0.27
Losh et al. (2009)	TD 34/7	23.4 (5.6)	FSIQ: 108.3 (15)	Q: - SI: ADI- R, ADOS NSCA: clinical diagnosis CLAS: DSM-IV	ToH	Total moves	g = 0.27
Low et al. (2009)	ASD 23/4	5.3–13.1/ 8.3 (2.2)	Not assessed	Q: - SI: - NSCA: clinical diagnosis CLAS: DSM-IV	Mazes	Accuracy	g = 0.63
Low et al. (2009)	TD 23/4	4.5–10.7/ 6.6 (1.3)	Not assessed	Q: - SI: - NSCA: clinical diagnosis CLAS: DSM-IV	Mazes	Accuracy	g = 0.63
McCrimmon et al. (2012)	AS 26/7	16–21/ 18.8 (1.6)	IQ ≥ 85 FSIQ: 113.2 (10.6) VIQ: 114.1 (12.2) PIQ: 108.9 (9.9)	Q: - SI: - NSCA: clinical diagnosis CLAS: DSM-IV-TR	Tower (D-KEFS)	Total score	g = 0.07
McCrimmon et al. (2012)	TD 26/7	16–21/ 18.9 (1.6)	FSIQ: 110.1 (8.8) VIQ: 109 (10.7) PIQ: 108.7 (10)	Q: - SI: - NSCA: clinical diagnosis CLAS: DSM-IV-TR	Tower (D-KEFS)	Total score	g = 0.07
Medeiros & Winsler (2014)	ASD 26/1	7–18/ 11.9 (2.7)	Not assessed	Q: - SI: - NSCA: clinical diagnosis CLAS: DSM-IV	ToH-Revised	Total moves	g = 0.51
Medeiros & Winsler (2014)	TD 18/8	7–18/ 10.3 (3.2)	Not assessed	Q: - SI: - NSCA: clinical diagnosis CLAS: DSM-IV	ToH-Revised	Total moves	g = 0.51
Ozonoff & Jensen (1999)	ASD 40	12.6 (3.4)	IQ ≥ 70 FSIQ: 95.2 (18.8) VIQ: 93.3 (20.0) PIQ: 98.6 (19.8)	Q: - SI: ADI-R, ADOS NSCA: clinical diagnosis CLAS: DSM-IV	ToH	Total score	g = 0.70
Ozonoff & Jensen (1999)	TD 29	12.1 (3.0)	FSIQ: 107.8 (10.8) VIQ: 107.8 (12.3) PIQ: 106.8 (12.5)		ToH	Total score	g = 0.70
Ozonoff et al. (2004)	ASD 72/7	6–47/ 15.7 (8.7)	FSIQ: 106.3 (16.3) VIQ: 104.9 (17.9) PIQ: 106 (16)	Q: - SI: ADI-R, ADOS-G NSCA: clinical diagnosis CLAS: ICD-10	SoC	Total perfect solutions	g = 0.87
Ozonoff et al. (2004)	TD 58/12	6–47/ 16.0 (7.6)	FSIQ: 106 (11.5) VIQ: 106.1 (11.6) PIQ: 105 (12)		SoC	Total perfect solutions	g = 0.87
Panerai et al. (2014)	HFA 9/2	8.9 (3.1)	IQ ≥ 85 85–111	Q: - SI: - NSCA: clinical diagnosis CLAS: DSM-IV-TR	ToL	Total perfect solutions	g = 1.79
Panerai et al. (2014)	TD 6/3	9.7(2.6)	Not assessed within study	Q: - SI: - NSCA: clinical diagnosis CLAS: DSM-IV-TR	ToL	Total perfect solutions	g = 1.79
Pellicano et al. (2006)	ASD 35/5	4.1–7.3/ 5.6 (0.9)	IQ ≥ 80 VIQ (PPVT): 82–122/ 101.2 (11) PIQ (Leiter): 83–141/ 113.6 (14.1)	Q: SCQ (P) SI: ADI-R NSCA: clinical diagnosis CLAS: DSM-IV/ICD-10	Mazes	Accuracy	g = 0.63
Pellicano et al. (2006)	TD 31/9	4-7.3/ 5.5. (0.9)	VIQ (PPVT): 75–121/ 103.3 (9.9) PIQ (Leiter): 91–143/ 112.52 (14.47)		ToL	Total perfect solutions	g = 0.63
Verbal (VIQ) and nonverbal IQ (PIQ) were assessed with the Peabody Picture Vocabulary Test (PPVT) and the Leiter International Performance Scale (Leiter), which does not allow an estimation of total IQ (FSIQ)
Pellicano (2007)	ASD 25/5	4.1–7.3/ 5.6 (0.9)	VIQ (PPVT): 85–122/ 100 (10.6) PIQ (Leiter): 85–141/ 113.9 (13.7)	Q: SCQ (P) S: ADI-R NSCA: clinical diagnosis CLAS: DSM-IV	Mazes	Accuracy	g = 0.54
Pellicano (2007)	TD 31/9	4-7.3/ 5.5 (0.9)	VIQ (PVVT): 75–121/ 103.3 (9.9) PIQ (Leiter): 91–143/ 112.5 (14.5)	Q: SCQ (P) S: ADI-R NSCA: clinical diagnosis CLAS: DSM-IV	ToL	Total perfect solutions	g = 0.54
VIQ and PIQ were assessed with the PPVT and the Leiter, which does not allow an estimation of FSIQ
Pellicano (2010)	ASD 40/5	T1: 4.1–7.3/ 5.6 (0.9)	IQ ≥ 80 T1: VIQ: 80–122/ 97.1 (11.5) PIQ: 83–141/ 113.3 (13.9)	Q: - SI: ADI-R, ADOS-G NSCA: clinical diagnosis CLAS: DSM-IV	ToL	T1: total perfect solutions	g = 1.54
Pellicano (2010)	TD 37/8	T1: 4-7.3/ 5.4 (0.9)	T1: VIQ: 87–120/ 100.9 (8.7) PIQ: 89–147/ 115.6 (16.4)		ToL	T1: total perfect solutions	g = 1.54
VIQ and PIQ were assessed with the PPVT and the Leiter, which does not allow an estimation of FSIQ
Planche & Lemonnier (2012)	HFA 14/1 + AS 13/2	6.1–10.2/ 8.4 (1.5)	IQ ≥ 70 FSIQ: 101.8 (21.5)	Q: - SI: ADI-R NSCA: clinical diagnosis CLAS: ICD-10	Tower (NEPSY)	Total score	g = −0.04
Planche & Lemonnier (2012)	TD 12/3	6–10/ 9.1 (1.4)	FSIQ: 106.2 (8.3)	Q: - SI: ADI-R NSCA: clinical diagnosis CLAS: ICD-10	Tower (NEPSY)	Total score	g = −0.04
Prior & Hoffmann (1990)	ASD 9/3	10.2–17.3/ 3.8	FSIQ (Leiter): 76–109/ 88	Q: - SI: - NSCA: clinical diagnosis CLAS: Rutter (1978)	Milner mazes	Number of errors	g = 1.32
Prior & Hoffmann (1990)	TD 9/3	10.3–17/ 13.8	FSIQ (Leiter): 85–112 / 100	Q: - SI: - NSCA: clinical diagnosis CLAS: Rutter (1978)	Milner mazes	Number of errors	g = 1.32
Rajendran et al. (2005)	ASD 8/4	11.4/ 16.5 (6.8)	FSIQ: 102 (21.5) VIQ: 110.3 (22.5) PIQ: 93.3 (22.8)	Q: - SI: - NSCA: clinical diagnosis CLAS: DSM-IV-TR	Zoo Map test	Summary profile score	g = 0.68
Rajendran et al. (2005)	TD 8/4	12–39/ 16.8 (7.4)	FSIQ: 109 (13) VIQ: 111.8 (14.3) PIQ: 104.5 (14.4)	Q: - SI: - NSCA: clinical diagnosis CLAS: DSM-IV-TR	Key Search test	Summary profile score	g = 0.68
Rajendran et al. (2011)	ASD 16/2	11.6–17.4/ 13.9 (1.7)	FSIQ: 96.2 (13.1) VIQ: 106.2 (14.6) PIQ: 87.6 (14.8)	Q: SCQ (P) SI: - NSCA: clinical diagnosis CLAS: DSM-IV-TR	Six Elements test	Summary profile score	g = 0.85
Rajendran et al. (2011)	TD 14/4	12.2–18.3/ 13.8 (1.4)	FSIQ: 106.8 (10) VIQ: 106.4 (12.2) PIQ: 106.1 (8.9)		Six Elements test	Summary profile score	g = 0.85
Robinson et al. (2009)	ASD 42/12	8–17/ 12.5 (2.8)	IQ ≥ 70 FSIQ: 103.5 (10.5)	Q: SCQ (P) SI: - NSCA: clinical diagnosis CLAS: DSM-IV	ToL	Total moves	g = −0.53
Robinson et al. (2009)	TD 42/12	8–17/ 12.1 (2.3)	FSIQ: 104.8 (9.1)	Q: SCQ (P) SI: - NSCA: clinical diagnosis CLAS: DSM-IV	ToL	Total moves	g = −0.53
Sachse et al. (2013)	HFA 27/3	14–33/ 19.2 (5.1)	IQ ≥ 70 FSIQ: 105.3 (12.3)	Q: - SI: ADI-R. ADOS NSCA: - CLAS: DSM-IV-TR	SoC	Total perfect solutions	g = 0.37
Sachse et al. (2013)	TD 24/4	14–33/ 19.9 (3.6)	FSIQ: 109.3 (11.5)	Q: - SI: ADI-R. ADOS NSCA: - CLAS: DSM-IV-TR	SoC	Total perfect solutions	g = 0.37
Schurink et al. (2012)	PDD-NOS 19/9	7–12/ 10.5 (1.4)	IQ ≥ 70 FSIQ: 81.4 (8.4)	Q: CSBQ (P) SI: - NSCA: clinical diagnosis CLAS: DSM-IV-TR	ToL	ToL score	g = 0.60
Schurink et al. (2012)	TD 19/9	7–12/ 10.4 (1.3)	Not reported	Q: CSBQ (P) SI: - NSCA: clinical diagnosis CLAS: DSM-IV-TR	ToL	ToL score	g = 0.60
Semrud-Clikeman et al. (2010)	ASD 8/7	9.1–16.5/ 10.6 (2.6)	IQ ≥ 80 FSIQ: 100.8 (13)	Q: - SI: ADI-R, ADOS NSCA: clinical diagnosis CLAS: DSM-IV	Tower (D-KEFS)	Total achievement	g = 0.82
Semrud-Clikeman et al. (2010)	TD 23/9	9.1–16.5/ 9.8 (2.1)	FSIQ: 109.4 (10)	Q: - SI: ADI-R, ADOS NSCA: clinical diagnosis CLAS: DSM-IV	Tower (D-KEFS)	Total achievement	g = 0.82
Sinzig et al. (2008)	ASD 16/4	8.3–18.9/ 14.3 (3.0)	IQ ≥ 80 PIQ: 112 (17.7)	Q: - SI: ADI-R, ADOS NSCA: clinical diagnosis CLAS: DSM-IV-TR	SoC	Total perfect solutions	g = 0.07
Sinzig et al. (2008)	TD 14/6	7.6–17.6/ 13.1 (3.0)	PIQ: 113 (11.9)		SoC	Total perfect solutions	g = 0.07
IQ (nonverbal) was measured using the Culture Fair Intelligence Test, which only assesses nonverbal IQ (PIQ)
Taddei & Contena (2013)	ASD 30/8	13.1 (3.3)	Not assessed	Q: - SI: - NSCA: clinical diagnosis CLAS: DSM-IV-TR, ICD-10	Cognitive Assessment System (CAS) - Planning	Total score	g = 2.27
Taddei & Contena (2013)	TD 10/5	12 (2.85)	Not assessed	Q: - SI: - NSCA: clinical diagnosis CLAS: DSM-IV-TR, ICD-10	Cognitive Assessment System (CAS) - Planning	Total score	g = 2.27
Unterrainer et al. (2015)	ASD 18	10.1 (2.4)	IQ ≥ 70 FSIQ: 97.1 (16.4)	Q: SRS SI: ADOS-G, ADI-R NSCA: clinical diagnosis CLAS: DSM-IV-TR/ ICD-10	ToL (computerized)	Total perfect solutions	g = 0.13
Unterrainer et al. (2015)	TD 42	9.8 (2.4)	FSIQ: 97.6 (13.9)		ToL (computerized)	Total perfect solutions	g = 0.13
Van Eylen et al. (2015)	ASD 30/20	8–18/ 12.2 (2.6)	IQ ≥ 70 FSIQ: 104.3 (10.8) VIQ: 104.3 (15.9) PIQ: 104.3 (13.2)	Q: SRS SI: 3Di NSCA: clinical diagnosis CLAS: DSM-IV-TR	Tower (D-KEFS)	Total score	g = 0.20
Van Eylen et al. (2015)	TD 30/20	8–18/ 12.5 (2.7)	FSIQ: 107.7 (9.3) VIQ: 111.6 (11.4) PIQ: 103.8 (13.7)		Tower (D-KEFS)	Total score	g = 0.20
Verté et al. (2005)	HFA 57/4	6–13/ 9.1 (1.9)	IQ ≥ 80 FSIQ: 99.2 (17.1)	Q: - SI: ADI-R, DISC-IV NSCA: clinical diagnosis CLAS: DSM-IV	ToL	ToL score	g = 0.82
Verté et al. (2005)	TD 40/7	6–13/ 9.4 (1.6)	FSIQ: 112.1 (9.7)		ToL	ToL score	g = 0.82
Verté et al. (2006)	ASD 99/13	6–13/ 8.6 (1.8)	IQ ≥ 80 FSIQ: 100.6 (16) VIQ: 97.3 (17.6) PIQ: 104.6 (17.6)	Q: - SI: ADI-R, DISC-IV NSCA: clinical diagnosis CLAS: DSM-IV-TR	ToL	ToL score	g = 0.68
Verté et al. (2006)	TD 40/7	6–13/ 9.4 (1.6)	FSIQ: 112.1 (9.7) VIQ: 113.6 (10.4) PIQ: 108.5 (11.9)		ToL	ToL score	g = 0.68
Wallace et al. (2009)	ASD 26/2	12–20/ 15.7 (2.1)	IQ ≥ 80 FSIQ: 110.3 (16.8) VIQ: 109.7 (17.1) PIQ: 108.8 (16.8)	Q: - SI: ADI-R, ADOS NSCA: clinical diagnosis CLAS: DSM-IV	ToL-Dx	Excess moves	g = 0.63
Wallace et al. (2009)	TD 24/1	12–19/ 16.4 (1.8)	FSIQ: 113.8 (10) VIQ: 111.9 (10.8) PIQ: 112.5 (10.3)		ToL-Dx	Excess moves	g = 0.63
White et al. (2009)	ASD 41/4	7–12/ 9.6 (1.4)	FSIQ: 105.9 (12.1) VIQ: 111 (14.7) PIQ: 98 (11.2)	Q: - SI: 3Di NSCA: clinical diagnosis CLAS: -	Zoo Map test	Accuracy Map 1	g = 0.41
White et al. (2009)	TD 21/6	7–12/ 9.9 (1.3)	FSIQ: 110.7 (14.6) VIQ: 115 (15.8) PIQ: 103 (12.4)		Key Search test	Total score	g = 0.41
Williams & Jarrold (2013)	ASD 21	10.45 (2.10)	VIQ: 103.3 (18) PIQ: 110 (16.4)	Q: SRS (P) SI: 3Di NSCA: clinical diagnosis CLAS: DSM-IV-TR, ICD-10	ToL	Total moves (manual version)	g = 0.59
Williams & Jarrold (2013)	TD 22	10.61 (1.3)	VIQ: 105.6 (13.3) PIQ: 107.2 (13)		ToL	Total moves (manual version)	g = 0.59
Participants also completed a computerized version of the ToL, which gave the same results (ns)
Williams et al. (2012)	ASD 17	42.13	FSIQ: 114 (13.4) VIQ: 112.8 (11.8) PIQ: 112.8 (15.3)	Q: AQ SI: ADOS NSCA: clinical diagnosis CLAS: DSM-IV-TR, ICD-10	ToL	Total moves silent condition	g = 0.26
Williams et al. (2012)	TD 17	39.43	FSIQ: 116.7 (13.3) VIQ: 117.6 (13.1) PIQ: 112.6 (11.1)		ToL	Total moves silent condition	g = 0.26
Please note that for the ToL test, n_ASD = 15 and n_tD = 16
Williams et al. (2014)^b	ASD 65	8–46/ 18.8 (9.7)	FSIQ: 98.8 (14) VIQ: 102 (15.6)	Q: - SI: ADI-R, ADOS NSCA: clinical diagnosis CLAS: DSM-IV-TR	ToH	Total moves	g = 0.24
	ASD 65	8–46/ 18.8 (9.7)	FSIQ: 98.8 (14) VIQ: 102 (15.6)		Zoo Map test	Summary profile score
	TD 65	8–46/ 19.2 (10.1)	FSIQ: 102.1 (8.8) VIQ: 102.6 (8.9)		Key Search test	Summary profile score
Zinke et al. (2010)	HFA 13/2	7–12/ 9.0 (1.5)	≥ 78 96.4 (14.5)	Q: - SI: ADI-R, ADOS NSCA: - CLAS: ICD-10	ToL	Total perfect solutions	g = 0.98
Zinke et al. (2010)	TD 14/3	6–12/ 9.8 (1.7)	Not reported	Q: - SI: ADI-R, ADOS NSCA: - CLAS: ICD-10	ToL	Total perfect solutions	g = 0.98

A Author; ADI-R Autism Diagnostic Interview Revised; ADOS(-G) Autism Diagnostic Observation Schedule(-Generic); AS Asperger Syndrome; ASD Autism spectrum disorder (could include autism, Asperger syndrome or PDD-NOS); AQ Autism Spectrum Questionnaire; CARS-II Childhood Autism Rating Scale, second edition; CAST Childhood Autism Spectrum Test; CLAS Classification system used; CSBQ (P) Children’s Social Behavior Questionnaire (Parent version); DART Dutch Adult Reading Test; DAS Differential Ability Scales; DAWBA Development and Wellbeing Assessment; DISC-IV (P) Diagnostic Interview Schedule for Children for DSM-IV, (parent version); D-KEFS Delis-Kaplan Executive Function System; DSM-IV(-TR) Diagnostic and Statistical Manual of Mental Disorders, fourth edition, (text-revised); F Female; FSIQ Full Scale Intelligence Quotient; GARS Gilliam Autism Rating Scale; HFA High Functioning Autism; ICD-10; International statistical classification of diseases and related health problems, tenth edition; IQ Intelligence Quotient; M male; NEPSY Developmental NEuroPSYchological Assessment; ns Did not reach statistical significance; NSCA Nonstructural clinical assessment; P Parent; PIQ Performance Intelligence Quotient; Q Questionnaire; RT Reaction Time; SCQ Social Communication Questionnaire; SI Structured instrument such as specially developed standardized interviews and observation schedules; SoC Stockings of Cambridge; SRS Social Responsiveness Scale; TD Typically developing group; ToH Tower of Hanoi; ToH-Revised Tower of Hanoi-Revised; ToL Tower of London; ToL-Dx Tower of London-Drexel; VIQ Verbal Intelligence Quotient; WADIC Wing’s Autistic Disorder Interview Checklist; 3Di Developmental, Dimensional and Diagnostic Interview

^aIf only one digit is reported, this refers to the total sample size because the division of gender (number of males and females) was unknown

^bWhen multiple planning tasks of different type of tasks were assessed within the same study, we chose type of task (Tower, BADS, CANTAB) for the moderator analysis of task-type based on the highest number of similar type of task available (e.g., Williams et al. (2014) is categorized as BADS)