One of the biggest challenges in infant sleep (and human sleep in general) is understanding why we don’t all sleep the same way. The most relevant research presented shows: 

• Multifactorial nature: Our biological clock is influenced by genetics, but also by habits and environment. 
• Genetic architecture: More than 650 circadian genetic variants have been identified in the human body. 
• Localization: These genetic variants are not only found in the brain, they are especially present in the gut and adrenal glands. 
• The role of the X chromosome: 20% of these variants are located here, adding another layer of complexity to individual development. 

Genetic impact influences: 

• Insomnia 
• Chronotype (early bird vs. night owl) 
• Sleep duration 

Sleep is not just behavioral. It is biological, genetic, and deeply individual. 

Step-by-Step Practical Application 

As a sleep consultant, these findings transform your approach: 

• Step 1: Assess chronotype. Identify whether the person is an early bird, a night owl, or intermediate. Avoid imposing standard routines without considering this. 

• Step 2: Analyze family history. Ask: How do caregivers sleep? Is there a history of insomnia? This provides clues about the genetic component. 

• Step 3: Detect misalignment. Look for: Difficulty falling asleep at “expected” times. Frequent awakenings without a clear behavioral cause. Think circadian misalignment, not just “bad habits.” 

• Step 4: Adapt, don’t force. Instead of “fixing,” focus on aligning the environment and routine with the individual’s biology. Examples: gradual schedule adjustments, natural light exposure, nap timing. 

• Step 5: Personalize interventions. Understand that what works for one child may not work for another… This explains why some families “do everything right” and still struggle. 

About the Author: Anahí Porto, APSC Latin America and South America RD. Graduate and professor in Psychology, Universidad de Buenos Aires. Master’s in Child and Adolescent Clinical Psychology, Sorbonne Paris Nord University, France. Former concurrent at Delafontaine Hospital (Saint-Denis, France). Anahí is based in Buenos Aires, Argentina. She is the founder and director of Instituto Profesional de Sueño Infantil. For more info, visit the site www.institutoprofesionalipsi.com.

Subscribe and view the blog post in Spanish here: https://substack.com/@institutoipsi