What are the expected developmental milestones for a 2-year-old child and what interventions are recommended if they are not met?

Expected Developmental Milestones at 2 Years of Age

By 24 months, children should demonstrate specific social-emotional, language, cognitive, and motor milestones, and any child not meeting these benchmarks requires immediate referral for comprehensive developmental evaluation and simultaneous initiation of early intervention services without waiting for formal diagnosis.

Core Developmental Milestones at 24 Months

Social-Emotional Development

• Points to show something interesting to others (joint attention behavior) 1
• Looks at your face to check your reaction in new situations 1
• Shows concern when others are hurt or upset (empathy development) 1
• Plays alongside other children and sometimes plays with them 1

Language and Communication

• Says at least 50 words 1
• Combines two words together (e.g., "more milk," "no bed") 1
• Points to at least two body parts when asked 1
• Uses more gestures than just waving and pointing (e.g., blowing a kiss, nodding yes) 1

Cognitive Development

• Holds something in one hand while using the other hand (bilateral coordination) 1
• Tries to use switches, knobs, or buttons on toys 1
• Plays with more than one toy at the same time (e.g., putting toy food on a toy plate) 1

Motor Development

• Kicks a ball 1
• Runs 1
• Walks up a few stairs with or without help 1
• Eats with a spoon 1

Red Flags Requiring Immediate Action

Critical Warning Signs

• Does not use two-word phrases by 24 months 1
• Does not know what to do with common objects (e.g., brush, phone, fork, spoon) 1
• Does not copy actions and words 1
• Loses skills previously acquired (regression in any domain) 1
• Does not follow simple instructions 1
• Does not walk steadily 1

Autism-Specific Red Flags

• Diminished orienting to eye region of faces (detectable from 2-6 months but becomes more apparent) 1
• Atypical trajectory of language development (slowing acquisition of new skills during second year) 1
• Lack of joint attention behaviors (not pointing to show interest, not checking parent's face) 1
• Repetitive or atypical motor behaviors 1
• Atypical sensory behaviors 1

Immediate Intervention Protocol When Milestones Are Not Met

Step 1: Formal Developmental Screening (Same-Day)

• Administer Ages and Stages Questionnaire, third edition (ASQ-3) with 86% specificity and 85% sensitivity 1
• The ASQ-3 can be completed by parents in the waiting room or sent by mail before the appointment, making it feasible for busy primary care settings 1
• If literacy is a barrier, complete via interview format 1

Step 2: Immediate Referral (Within 2 Days)

• Refer to multidisciplinary diagnostic team for comprehensive evaluation using gold-standard instruments including Autism Diagnostic Observation Schedule-Second Edition (ADOS-2) and Autism Diagnostic Interview-Revised (ADI-R) 2
• Simultaneously refer to early intervention program within 2 days of concern identification (federal requirement per CFR 303.321d) 1
• Do not wait for formal diagnosis completion before initiating interventions, as this delays critical early treatment 2

Step 3: Comprehensive Medical Evaluation

• Objective vision and hearing evaluation (mandatory for all children with developmental concerns) 1
• Blood lead level testing 1
• Metabolic screening if clinically indicated 1
• Genetic evaluation and counseling should be offered to all families, as this provides information on etiology, prognosis for progression, associated disorders (renal, vision, cardiac), and recurrence risk 1

Step 4: Initiate Intensive Behavioral Interventions (Before Age 3)

• Begin 20-30 hours per week of intensive, individualized interventions combining developmental and behavioral approaches 2, 3
• Interventions started before age 3 have significantly greater impact than those begun after age 5, making immediate initiation critical 2
• Include 5 hours per week of parent education and training as co-therapists 2, 3
• Evidence-based programs include Early Start Denver Model (ESDM) and Early Intensive Behavioral Intervention (EIBI), which demonstrate large effect sizes for joint attention skills and moderate effect sizes for expressive language after 6-8 weeks 2

Step 5: Target Core Deficits

• Joint attention skills (pointing to show interest, checking parent's face, shared attention) 2, 3
• Social communication and reciprocity 2, 4
• Emotional regulation 1
• Adaptive behaviors (self-care, daily living skills) 1

Delivery Settings and Family Involvement

Service Delivery Options

• Home-based (parent-managed), center-based (clinic or school), or combination depending on resources and child needs 3
• The key component is provider expertise specific to developmental delays or hearing loss, not the location 1

Mandatory Family Involvement

• Parents must function as co-therapists with appropriate supervision, training, and monitoring 1, 2
• Active family involvement increases intervention time, as children spend more time with parents than in clinical settings 1
• Parents can capitalize on teachable moments during daily routines and facilitate generalization of skills across environments 1
• Family involvement is cost-effective and increases parental empowerment 1

Critical Pitfalls to Avoid

Do Not Delay

• Never wait for formal diagnosis to begin interventions—the median time from concern to diagnosis is already too long (typically 3-4 years despite parental concerns by 18 months) 2
• Do not adopt a "wait and see" approach when developmental concerns are identified 2

Do Not Over-Test

• Do not order extensive medical testing routinely—genetic testing is indicated only with specific clinical indicators 2
• Focus resources on initiating interventions rather than exhaustive diagnostic workups 2

Do Not Use Medication First-Line

• Behavioral interventions are primary for developmental delays and autism spectrum disorder 2, 4
• Pharmacotherapy targets only specific symptoms or comorbid conditions, not core developmental deficits 4

Do Not Implement Interventions Without Family

• Interventions without active family involvement fail to achieve generalization and long-term success 1, 2, 3
• Parent training is not optional but essential 1, 3

Monitoring and Adjustment

Reassessment Timeline

• Reassess within 4-8 weeks of initiating interventions to determine response 3
• Adjust intervention intensity, focus, and strategies based on which specific deficits show improvement 3
• Use standardized measures including Bayley Scales of Infant and Toddler Development, Mullen Scales of Early Learning, or Battelle Developmental Inventory 1, 2

Outcome Expectations

• Children enrolled in early intervention within the first year of life have language development within the normal range at 5 years of age 1
• Infants identified in the first 6 months and provided immediate intervention have significantly better outcomes in vocabulary, receptive and expressive language, syntax, speech production, and social-emotional development compared to later-identified children 1