Research with Children

Who is a "Child" for Purposes of Research Participation?

By regulatory definition, children are “persons who have not attained the legal age for consent to treatments or procedures involved in the research, under the applicable law of the jurisdiction in which the research will be conducted” (45 CFR 46.402(a)). In the United States the legal age of adulthood is a matter of state and local law. This means that who is legally considered a child may vary from state to state; in a large majority of states 18 years of age is the legal age of adulthood, but this is not true in every state, locality, or territory. State law also may address specific circumstances in which a person younger than the age of adulthood is legally authorized to consent to medical procedures: for example, some states allow children younger than the legal age of adulthood to consent to the provision of contraceptive services. Certain states provide a mechanism for the emancipation of minors, through which a child younger than the legal age of adulthood may gain certain civil rights, which might include the legal ability to consent to research participation.

The definition of children also takes into account the particular interventions or interactions involved in the proposed research (e.g., surveys, blood tests). For example, in some places individuals who are 16 years of age may legally consent to certain clinical interventions or interactions. If the involvement of human subjects in a proposed research activity consists of these interventions or interactions, then those individuals may be considered as adults for that purpose. If a proposed activity includes an intervention or interaction for which the subject has not yet reached the legal age of consent, however, that person must be considered a child.

If you plan to conduct research in countries other than the United States, you need to check on the laws of those jurisdictions regarding who is considered a "child" for research purposes. 

Parental Permission and Assent

If your study will include children as research participants, the IRB must determine that adequate provisions are made for seeking parental/guardian permission and the assent of children (when in the judgment of the IRB the children are capable of providing assent).  Permission means the agreement of parent(s) or guardian to the participation of their child or ward in research (45 CFR 46.402(c)).  Children are unable to provide legally effective informed consent to participate in research – however, some children might be able to give their assent to participate in research.  Assent means a child’s affirmative agreement to participate in research. Mere failure to object should not, absent affirmative agreement, be construed as assent (45 CFR 46.402(b)).

The regulations set out categories of research with children that may be approved, based on the risks and potential benefit of the research (see 45 CFR 46.404 through 45 CFR 46.407).  For research that is not greater than minimal risk, 45 CFR 46.404 is the applicable category.  The IRB may find that the permission of one parent is sufficient for research to be conducted under 45 CFR 46.404 or 45 CFR 46.405. Where research is conducted under 45 CFR 46.406 or 45 CFR 46.407, permission must be obtained from both parents unless one parent is deceased, unknown, incompetent, or not reasonably available, or when only one parent has legal responsibility for the care and custody of the child.

Templates for parental permission and assent forms are available on the SBS IRB website at

Documenting children’s assent to participate: The IRB has the discretion to determine the appropriate manner, if any, of documenting child assent. Based on such considerations as the child’s age, maturity, and degree of literacy, the IRB will decide what form of documentation, if any, is most appropriate.

The process of asking a child to participate in research should be carefully planned and implemented, using age-appropriate language and methods, for any child who is capable of understanding and providing assent.  If a child is considered capable of being involved in the informational process (regardless of age), at least a simple verbal explanation of what will happen to him/her and the opportunity for questions and discussion should be given. 

The IRB recommends the following general guidelines for assent by age group of the child participants:

Children up to 7 years old:   The IRB can grant a waiver of assent if the capability of some or all of the children who will be participating in a study is so limited that they cannot reasonably be consulted.  Because the capability of children younger than age 7 to understand what it means to be in a research study is very limited, if all children who will be enrolled as participants in your study will be younger than 7 years old, then the requirement for assent will be waived.  In such cases, only parental permission is required (unless the research team requests a waiver of parental permission and the research qualifies for a waiver of parental permission).

Even if the IRB waives the requirement for assent, it is always preferable to involve the child in the process as much as possible.  There should be documentation on the parental permission form or in the study records that the child was informed about the study.

Children 7 to 12 years old: In most cases, children in this age range will be able to participate in the assent process using a simplified assent form or script.  The child should sign the form if possible.  If not, the form or study records should still document that verbal assent was obtained.  Parental permission must be obtained (unless the research team requests a waiver of parental permission and  the research qualifies for a waiver of parental permission.)

Children 13 to 17 years old: In most cases, adolescents should be fully informed about a study and give signed assent to their own participation in a research study.    Depending on the complexity of the study and the condition/capacity of the adolescent participants, an adolescent assent form may be very similar to the parental permission form or it may need to be somewhat simpler than the adult's form.  In situations where the parental permission form will be identical to the adolescent assent form, the researcher may propose using one parental permission/child assent form, with signature lines for both the parent and the adolescent.

When a child reaches the legal age of consent while enrolled in a study: Informed consent should be viewed as an ongoing process throughout the duration of a research project. When a child who was enrolled in research with parental or guardian permission subsequently reaches the legal age of consent to the procedures involved in ongoing research, the subject’s participation in the research is no longer regulated by the requirements regarding parental/guardian permission and subject assent.

Unless the IRB determines that the requirements for obtaining informed consent can be waived, the investigators should seek and obtain the legally effective informed consent for the now-adult subject for any ongoing interactions or interventions with the subjects. This is because the prior parental permission and child assent are not equivalent to legally effective informed consent for the now-adult subject. However, the IRB could approve a waiver of informed consent under 45 CFR 46.116(d), if the IRB finds and documents that the required conditions are met.

Similarly, if the research does not involve any ongoing interactions or interventions with the subjects, but continues to meet the regulatory definition of “human subjects research” (e.g., it involves the continued analysis of specimens or data for which the subject’s identity is readily identifiable to the investigator(s)), then it would be necessary for the investigator(s) to seek and obtain the legally effective informed consent of the now-adult subjects. The IRB may consider, if appropriate, a waiver under 45 CFR 46.116(d) of the requirements for obtaining informed consent in order for the subjects to continue their participation in the research.

Waiver of Parental/Guardian Permission: An IRB may waive the requirements for obtaining parental or guardian permission if either of the following two conditions is met:

  1. The IRB makes and documents the required findings under either  45 CFR 46.116(c) or (d);


  1. The IRB determines that a research protocol is designed to study conditions in children or a subject population for which parental or guardian permission is not a reasonable requirement to protect the subjects (for example, neglected or abused children), and the following 2 additional criteria are also met:
    1. An appropriate mechanism is in place to protect the children, and
    2. The waiver is not inconsistent with federal, state, or local law (45 CFR 46.408(c)).

The choice of an appropriate substitute mechanism (for example, appointing a child advocate or an assent monitor) for protecting children participating in research would depend on the nature and purpose of the activities described in the protocol, the risk and anticipated benefit to the research subjects, and the child’s age, maturity, status, and condition.

Passive consent/opt-out situations: The term “passive consent” is sometimes used in research with children to describe situations in which the investigator can assume that a parent is permitting a child to participate. For example, researchers collecting survey and behavioral data from children at school provide parents with information regarding the study by mail and ask the parent(s) to return a form if they do not want their child to participate. Sometimes this practice is referred to as an opt-out procedure, which is not consistent with the regulatory requirement for seeking and obtaining parental permission. If the IRB determines that the conditions for waiver of parental permission can be met, then the IRB could waive the requirement for parental permission under 45 CFR 46.408(c) or 45 CFR 46.116(c) or (d). Even though not required by the regulations, an IRB may require that parents be given the opportunity to refuse permission even when the IRB has waived the regulatory requirement to obtain parental permission.

Waiver of Assent: The IRB is responsible for deciding whether child assent is required in proposed research activities. Child assent is required, except in the following three circumstances described at 45 CFR 46.408(a):

  1. the capability of some or all of the children is so limited that they cannot reasonably be consulted;
  2. the intervention or procedure involved in the research holds out the prospect of direct benefit to the health or well-being of the children and is available only in the context of the research;
  3. the research meets the same conditions as those for waiver or alteration of informed consent in research involving adults, as specified in the regulations at either 45 CFR 46.116(c) or 45 CFR 46.116(d).

Even when the IRB determines that the subjects are capable of assenting, the IRB may still waive the assent requirement under certain circumstances in accord with 45 CFR 46.116 and 45 CFR 46.408(a).

Impact of Other Statutes, Regulations, and Policies:

Mandatory Reporting of Suspected Child Abuse and Neglect: ALL University personnel are “mandated reporters” and must immediately report to a 24-hour hotline any instance where there is reasonable cause to believe that a child known to them in their official capacity is being abused or neglected. For more information, please see Mandatory Reporting of Suspected Child Abuse and Neglect.  Contact Ted Stamatakos in the Office of Legal Counsel with any questions: 773-702-7516,

Sponsor Requirements: If you are conducting research funded by a federal agency, you should be aware of any special requirements and restrictions the funding agency may place on your research.  For example the U.S. Department of Defense (DOD) has special requirements for DOD-funded research, including certain limitations on waivers of consent, DOD approval for surveys or interview questions administered to DOD personnel and their families, and additional protections for vulnerable subject populations.

FERPA:  If you plan to obtain information from student education records as part of your research, be aware that the Federal Education Rights and Privacy Act (FERPA) sets forth consent requirements (and exceptions) for accessing information in student education records. 

PPRA: The Protection of Pupil Rights Amendment (PPRA) (20 U.S.C. § 1232h; 34 CFR Part 98), also known as “Student Rights in Research, Experimental Programs, and Testing,” is a federal law that affords certain rights to parents of minor students with regard to surveys that ask questions of a personal nature.  The No Child Left Behind Act of 2001 contains a major amendment to PPRA that gives parents more rights with regard to the surveying of minor students, the collection of information from students for marketing purposes, and certain non-emergency medical examinations.

For further information about FERPA and PPRA, see the IRB website section on Research in Schools and with Education Records at

For further information on informed consent, parental permission, assent, and waivers/alterations of consent, please see the HHS Office of Human Research Protections Frequently Asked Questions at