The Infant Strange Situation (SSP)

Upcoming Dates


The Infant Strange Situation (SSP) is an instrument for assessing quality of attachment in 11-17-month-old infants. It was developed by Mary D. Salter Ainsworth and expanded by Mary Main and Judith Solomon (who added the notion of disorganisation) and Patricia M. Crittenden (who added the A/C and pre-compulsive classifications).

The Ainsworth Infant Strange Situation involves a 24-minute laboratory procedure and takes three people to carry out (plus the child and carer). Classification is based on careful review of the video.

The Dynamic Maturational Model (DMM) classificatory system includes all of the categories of the original infant procedure (i.e., A1-2, B1-4, C1-2), plus several patterns that would be identified as disorganisation by others, specifically, A/C, and the pre-compulsive patterns. These additions make the system suitable for a wider range of cultures and home environments, particularly those with risk for psychopathology.

The 12-day course is taught from video in 6 day blocks. Both adult and infant behaviour are assessed. Non-verbal behaviour, interpersonal strategies, and developmental processes are emphasised.

Following the basic course members may take an advanced clinical training.

Mandatory Course Requirements

It is essential that trainees attend all 12 days of the course. There will be practice coding during the training and in between the taught days. Not completing the practice is likely to seriously impede the level of reliability that can be achieved.

Competency to code is assessed by a reliability test after the training. The Family Relations Institute issues participants with a reliability certificate stating the percent agreement with the standard. This reliability can be reported. Evidence of reliability should be requested if the participant will code data for others.

Competence in administering the procedure is also assessed and therefore course participants are required to submit 3 satisfactorily administered Infant Strange Situations for feedback (two normative, 1 clinical). Feedback will be given for each procedure.

Course Timings

With the exception of the first and final days of each teaching block, training days will begin at 12.30pm and end between 5-6pm. You will be required to code a number of procedures before the training starts each day. Consequently, participants should be entirely free of other obligations during the training. The course will begin at 1pm on Day 1 and run from 9-1pm on the final day to allow for people to travel.


All teaching, weekly feedback on practice SSP’s and registration with Dr Crittenden for the reliability test. Crittenden’s Attachment and Psychopathology (A&P) course is a prerequisite to the SSP course. Course dates can be found here