Below a list of additional evidence submitted to the Education Committee following their invitation for views on the strength of the evidence in relation to the current policy on Summer Born Children and the effect of birth date on student achievement (my bold).

(Pottegård 2014) Children’s relative age in class and use of medication for ADHD: a Danish Nationwide Study.
Lack of relative age effect found “may be due to the high proportion (40%) of relatively young children held back by 1 year in the Danish school system”.

(Goodman 2003) Child psychiatric disorder and relative age within school year: cross sectional survey of large population sample.
“Younger children in a school year were significantly more likely to have higher symptom scores and psychiatric disorder… a more flexible approach to children’s progression through school might reduce the number of children with impairing psychiatric disorders in the general population… around 60,000 cases of child psychiatric disorder might be prevented…
“In New Zealand, children spend between 12 months and 24 months in a reception or preparatory class, with progression to the next class being determined by the child’s maturity and academic competence. Similarly, Scottish parents can choose to defer school entry for relatively young children who do not seem ready for school… In England and Wales… children must start school in the academic year during which they will become 5 years old.”

(Angus 2004) The relative age effect and the development of self-esteem.
“To date, relative age research has reported significant and substantial achievement differences within the confines of athletic and academic pursuits. However, with the advent of the study noted above, it now appears that emotional development is also implicated. Here we demonstrate that a relatively young age of entry into the formal educational system is associated with reduced self-esteem several years later.”

(Pote 1996) Reception class structure and the performance of summer-born children in key stage 1 assessments: A small scale study in a London borough. International Journal of Early Childhood
“In terms of equality of opportunity summer born children are not gaining equal access to the curriculum by virtue of their date of birth.”

(Cleborne 1981) School Entry Age in a Group of Gifted Children
“Since this study was conducted only in grades five through eight and in a state where entry was not allowed until age 6-0, it is reasonable to assume that replication with younger groups of gifted children, or in states which allow entry to first grade prior to age 6-0 in the absence of readiness testing would yield even more dramatic results.”
“In the absence of such programs, parents may wish to consider delaying first-grade entrance for those children who would be early entrants and who show signs of immaturity. States and/or school districts which allow entry to first grade prior to age 6-0 might consider revising this requirement upward, at least until and unless screening and testing programs are in place.”
“The results of this research actually argue for entry based on factors other than chronological age for all children, gifted or otherwise.”
“It seems likely that the age at entry phenomenon will continue to result in more early-entering children being placed in classes for children with learning problems, while fewer early-entering children are identified as gifted.”

(Head 1999) Understanding the Boyes: Issues of Behaviour and Achievement.
Too early formalisation of learning is known to affect boys more profoundly than girls and the likely consequence is boys’ alienation from education and learning.

(Bedard 2006) The persistence of early childhood maturity: international evidence of long-run age effects
“These findings suggest that retention may partly ameliorate the disadvantage of being relatively young… In general, the low failure rate countries (England, Iceland, Japan, and Norway) have large relative age effects… countries that employ social promotion (automatic promotion from one grade to the next) and claim to have only one track are implicitly streaming to the extent that the weakest students are allowed to fall progressively farther behind… In particular, there is no evidence of relative age effects in Denmark or Finland. However, one should expect weak relative age effects in countries where formal curriculum based education begins later because initial age differences will be less important.”

(RR424 DFES; Malcolm 2003) Absence from School: A study of its causes and effects in seven LEAs.
“Key findings indicate that: Most LEAs and teachers thought that absence led to underachievement; Teachers could not always give children the help they needed to make up lost time; Secondary school teachers believed that academic underachievement would damage children’s future job prospects.”

(Tymms 2004) Children starting school in Scotland
“There was a stronger relationship [between age and measured attainment] in England. That is to be expected, at least to some extent, since the mean age of children starting school was lower than in Scotland and age is a more important factor for younger children than older.”

(Bernardi 2014) A Regression Discontinuity Based on Month of Birth
Italy: “Results indicate that students born just before the cutoff date for primary school entry, who are consequently the youngest in the class when starting school, face a larger risk of grade repetition. In line with theoretical predictions of the compensatory advantage model, the risk is much smaller for students born to highly educated parents compared to students whose parents have lower educational attainment.” [Except in England, we rarely employ grade repetition, so a SB child seriously struggling in Year 1 or 2 for example will simply continue with his year group regardless.]

(Sharp 1995) What’s age got to do with it? A study of patterns of school entry and the impact of season of birth on school attainment
“Data from [KS1 and GCSE] assessments confirm that children who are older in the year‐group perform best (although there are some anomalies evident in the month on month trends). It is argued that these findings are due to the differences in age when taking the tests, but may also be influenced by ‘age‐position effects’ and entry policies.”