To identify molecular mechanisms by which early life social conditions might influence adult risk of disease in rhesus macaques (Macaca mulatta), we analyze changes in basal leukocyte gene expression profiles in 4-mo-old animals reared under adverse social conditions. Compared with the basal condition of maternal rearing (MR), leukocytes from peer-reared (PR) animals and PR animals provided with an inanimate surrogate mother (surrogate/peer reared, SPR) show enhanced expression of genes involved in inflammation, cytokine signaling, and T-lymphocyte activation, and suppression of genes involved in several innate antimicrobial defenses including type I interferon (IFN) antiviral responses. Promoter-based bioinformatic analyses implicate increased activity of CREB and NF-κB transcription factors and decreased activity of IFN response factors (IRFs) in structuring the observed differences in gene expression. Transcript origin analyses identify monocytes and CD4(+) T lymphocytes as primary cellular mediators of transcriptional up-regulation and B lymphocytes as major sources of down-regulated genes. These findings show that adverse social conditions can become embedded within the basal transcriptome of primate immune cells within the first 4 mo of life, and they implicate sympathetic nervous system-linked transcription control pathways as candidate mediators of those effects and potential targets for health-protective intervention.