diff --git a/R/buildComponent.R b/R/buildComponent.R
index cff3268e..71f28929 100644
--- a/R/buildComponent.R
+++ b/R/buildComponent.R
@@ -19,7 +19,7 @@
 #' @param isChild_method character. The method to use for computing the isChild matrix.  Options are "classic" or "partialparent"
 #' @param adjBeta_method numeric The method to use for computing the building the adjacency_method matrix when using the "beta" build
 #' @param compress logical. If TRUE, use compression when saving the checkpoint files.  Defaults to TRUE.
-#' @param mz_twins logical. If TRUE, treat MZ twins as having an additional parent-child relationship for the purposes of computing the relatedness matrix. Defaults to FALSE.
+#' @param mz_twins logical. If TRUE, merge MZ co-twin columns in the r2 matrix before tcrossprod so that MZ twins are coded with relatedness 1 instead of 0.5. Twin pairs are identified from the \code{twinID} column. When a \code{zygosity} column is also present, only pairs where both members have \code{zygosity == "MZ"} are used; otherwise all \code{twinID} pairs are assumed to be MZ. Defaults to FALSE.
 #' @param ... additional arguments to be passed to \code{\link{ped2com}}
 #' @details The algorithms and methodologies used in this function are further discussed and exemplified in the vignette titled "examplePedigreeFunctions". For more advanced scenarios and detailed explanations, consult this vignette.
 #' @export
@@ -123,9 +123,9 @@ ped2com <- function(ped, component,
     ped <- standardizeColnames(ped, verbose = config$verbose)
   }
 
+  mz_pairs <- NULL
   if (mz_twins == TRUE && "twinID" %in% colnames(ped)) {
-    # TODO
-    # ped <- addMZtwins(ped, verbose = config$verbose)
+    mz_pairs <- findMZtwins(ped, verbose = config$verbose)
   }
 
 
@@ -289,6 +289,22 @@ ped2com <- function(ped, component,
     compress = config$compress
   )
 
+  # --- Step 3b: Temporarily merge MZ twin columns in r2 ---
+  # MZ twins share the same genetic source.  We absorb twin2's column into
+  # twin1's before tcrossprod so all path-traced relatedness flows through a
+  # single source.  After tcrossprod we copy twin1's row/col back to twin2.
+  if (!is.null(mz_pairs) && length(mz_pairs) > 0) {
+    for (pair in mz_pairs) {
+      idx1 <- pair[1]
+      idx2 <- pair[2]
+      r2[, idx1] <- r2[, idx1] + r2[, idx2]
+      r2[, idx2] <- 0
+    }
+    if (config$verbose == TRUE) {
+      message("Merged ", length(mz_pairs), " MZ twin pair column(s) in r2")
+    }
+  }
+
   # --- Step 4: T crossproduct  ---
 
   if (config$resume == TRUE && file.exists(checkpoint_files$tcrossprod_checkpoint) &&
@@ -308,6 +324,20 @@ ped2com <- function(ped, component,
     }
   }
 
+  # --- Step 4b: Restore MZ twins ---
+  # Copy twin1's row/col to twin2 so both twins appear in the final matrix.
+  if (!is.null(mz_pairs) && length(mz_pairs) > 0) {
+    for (pair in mz_pairs) {
+      idx1 <- pair[1]
+      idx2 <- pair[2]
+      r[idx2, ] <- r[idx1, ]
+      r[, idx2] <- r[, idx1]
+    }
+    if (config$verbose == TRUE) {
+      message("Restored ", length(mz_pairs), " MZ twin pair(s) in relatedness matrix")
+    }
+  }
+
   if (config$component %in% c("mitochondrial", "mtdna", "mitochondria")) {
     r@x <- rep(1, length(r@x))
     # Assign 1 to all nonzero elements for mitochondrial component
@@ -343,6 +373,7 @@ ped2add <- function(ped, max_gen = 25, sparse = TRUE, verbose = FALSE,
                     save_rate_parlist = 100000 * save_rate,
                     save_path = "checkpoint/",
                     compress = TRUE,
+                    mz_twins = FALSE,
                     ...) {
   ped2com(
     ped = ped,
@@ -361,6 +392,7 @@ ped2add <- function(ped, max_gen = 25, sparse = TRUE, verbose = FALSE,
     save_rate_parlist = save_rate_parlist,
     save_path = save_path,
     compress = compress,
+    mz_twins = mz_twins,
     ...
   )
 }
diff --git a/R/constructAdjacency.R b/R/constructAdjacency.R
index 3053fb5b..d779937b 100644
--- a/R/constructAdjacency.R
+++ b/R/constructAdjacency.R
@@ -559,3 +559,70 @@ isChild <- function(isChild_method, ped) {
     })
   }
 }
+
+
+#' Find MZ twin pairs in a pedigree
+#'
+#' Identifies MZ twin pairs from the \code{twinID} column and returns their
+#' row indices.  These indices are used later to merge the twins' columns in
+#' the \code{r2} matrix before \code{tcrossprod}, which correctly produces
+#' relatedness 1 between MZ co-twins with no diagonal or downstream artifacts.
+#'
+#' @param ped A pedigree data.frame with columns \code{ID} and \code{twinID}.
+#'   Optionally a \code{zygosity} column; when present only pairs where both
+#'   members have \code{zygosity == "MZ"} are used.
+#' @param verbose logical. If TRUE, print progress messages.
+#' @return A list of length-2 integer vectors \code{c(idx1, idx2)} giving the
+#'   row indices of each MZ pair in the pedigree, or \code{NULL} if none found.
+#' @keywords internal
+findMZtwins <- function(ped, verbose = FALSE) {
+  if (!"twinID" %in% colnames(ped)) {
+    return(NULL)
+  }
+
+  twin_rows <- which(!is.na(ped$twinID))
+
+  # If zygosity column exists, restrict to MZ pairs
+  if ("zygosity" %in% colnames(ped)) {
+    twin_rows <- twin_rows[!is.na(ped$zygosity[twin_rows]) &
+      ped$zygosity[twin_rows] %in% c("mz", "MZ")]
+  }
+
+  if (length(twin_rows) == 0) {
+    return(NULL)
+  }
+
+  processed <- c()
+  pairs <- list()
+
+  for (idx in twin_rows) {
+    twin_id <- ped$ID[idx]
+    co_twin_id <- ped$twinID[idx]
+
+    # Skip if already processed this pair
+    if (twin_id %in% processed || co_twin_id %in% processed) next
+
+    idx1 <- which(ped$ID == twin_id)
+    idx2 <- which(ped$ID == co_twin_id)
+
+    if (length(idx1) != 1 || length(idx2) != 1) next
+
+    # Always put the lower index first for consistency
+    if (idx1 > idx2) {
+      tmp <- idx1
+      idx1 <- idx2
+      idx2 <- tmp
+    }
+
+    processed <- c(processed, twin_id, co_twin_id)
+    pairs[[length(pairs) + 1]] <- c(idx1, idx2)
+
+    if (verbose) {
+      message("MZ twin pair found: ", twin_id, " (row ", idx1,
+        ") and ", co_twin_id, " (row ", idx2, ")")
+    }
+  }
+
+  if (length(pairs) == 0) return(NULL)
+  return(pairs)
+}
diff --git a/man/adjustKidsPerCouple.Rd b/man/adjustKidsPerCouple.Rd
index bf5b8192..dbe7e500 100644
--- a/man/adjustKidsPerCouple.Rd
+++ b/man/adjustKidsPerCouple.Rd
@@ -21,7 +21,18 @@ value is 3. Returns an error when kpc equals 1.}
 generated from a poisson distribution with mean kpc. If FALSE, the number of
 kids per mate will be fixed at kpc.}
 
-\item{beta}{logical. If TRUE, use the optimized version of the algorithm.}
+\item{beta}{logical or character. Controls which algorithm version to use:
+\itemize{
+  \item{\code{FALSE}, \code{"base"}, or \code{"original"} (default): Use the original algorithm.
+        Slower but ensures exact reproducibility with set.seed().}
+  \item{\code{TRUE} or \code{"optimized"}: Use the optimized algorithm with 4-5x speedup.
+        Produces statistically equivalent results but not identical to base version
+        due to different random number consumption. Recommended for large simulations
+        where speed matters more than exact reproducibility.}
+}
+Note: Both versions are mathematically correct and produce valid pedigrees with the
+same statistical properties (sex ratios, mating rates, etc.). The optimized version
+uses vectorized operations instead of loops, making it much faster for large pedigrees.}
 }
 \value{
 A numeric vector with the generated or adjusted number of kids per couple.
diff --git a/man/buildBetweenGenerations.Rd b/man/buildBetweenGenerations.Rd
index fa87604e..f28622b2 100644
--- a/man/buildBetweenGenerations.Rd
+++ b/man/buildBetweenGenerations.Rd
@@ -62,7 +62,18 @@ kids per mate will be fixed at kpc.}
 
 \item{code_female}{The value to use for females. Default is "F"}
 
-\item{beta}{logical. If TRUE, use the optimized version of the algorithm.}
+\item{beta}{logical or character. Controls which algorithm version to use:
+\itemize{
+  \item{\code{FALSE}, \code{"base"}, or \code{"original"} (default): Use the original algorithm.
+        Slower but ensures exact reproducibility with set.seed().}
+  \item{\code{TRUE} or \code{"optimized"}: Use the optimized algorithm with 4-5x speedup.
+        Produces statistically equivalent results but not identical to base version
+        due to different random number consumption. Recommended for large simulations
+        where speed matters more than exact reproducibility.}
+}
+Note: Both versions are mathematically correct and produce valid pedigrees with the
+same statistical properties (sex ratios, mating rates, etc.). The optimized version
+uses vectorized operations instead of loops, making it much faster for large pedigrees.}
 }
 \value{
 The function updates the `df_Fam` data frame in place, adding or modifying columns related to parental and offspring status,
diff --git a/man/buildWithinGenerations.Rd b/man/buildWithinGenerations.Rd
index 905e42ad..cbddf27a 100644
--- a/man/buildWithinGenerations.Rd
+++ b/man/buildWithinGenerations.Rd
@@ -20,7 +20,18 @@ buildWithinGenerations(
 )
 }
 \arguments{
-\item{beta}{logical. If TRUE, use the optimized version of the algorithm.}
+\item{beta}{logical or character. Controls which algorithm version to use:
+\itemize{
+  \item{\code{FALSE}, \code{"base"}, or \code{"original"} (default): Use the original algorithm.
+        Slower but ensures exact reproducibility with set.seed().}
+  \item{\code{TRUE} or \code{"optimized"}: Use the optimized algorithm with 4-5x speedup.
+        Produces statistically equivalent results but not identical to base version
+        due to different random number consumption. Recommended for large simulations
+        where speed matters more than exact reproducibility.}
+}
+Note: Both versions are mathematically correct and produce valid pedigrees with the
+same statistical properties (sex ratios, mating rates, etc.). The optimized version
+uses vectorized operations instead of loops, making it much faster for large pedigrees.}
 
 \item{sizeGens}{A numeric vector containing the sizes of each generation within the pedigree.}
 
diff --git a/man/findMZtwins.Rd b/man/findMZtwins.Rd
new file mode 100644
index 00000000..a265c4d2
--- /dev/null
+++ b/man/findMZtwins.Rd
@@ -0,0 +1,26 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/constructAdjacency.R
+\name{findMZtwins}
+\alias{findMZtwins}
+\title{Find MZ twin pairs in a pedigree}
+\usage{
+findMZtwins(ped, verbose = FALSE)
+}
+\arguments{
+\item{ped}{A pedigree data.frame with columns \code{ID} and \code{twinID}.
+Optionally a \code{zygosity} column; when present only pairs where both
+members have \code{zygosity == "MZ"} are used.}
+
+\item{verbose}{logical. If TRUE, print progress messages.}
+}
+\value{
+A list of length-2 integer vectors \code{c(idx1, idx2)} giving the
+  row indices of each MZ pair in the pedigree, or \code{NULL} if none found.
+}
+\description{
+Identifies MZ twin pairs from the \code{twinID} column and returns their
+row indices.  These indices are used later to merge the twins' columns in
+the \code{r2} matrix before \code{tcrossprod}, which correctly produces
+relatedness 1 between MZ co-twins with no diagonal or downstream artifacts.
+}
+\keyword{internal}
diff --git a/man/ped2add.Rd b/man/ped2add.Rd
index dc2fee88..a7e83f8d 100644
--- a/man/ped2add.Rd
+++ b/man/ped2add.Rd
@@ -21,6 +21,7 @@ ped2add(
   save_rate_parlist = 1e+05 * save_rate,
   save_path = "checkpoint/",
   compress = TRUE,
+  mz_twins = FALSE,
   ...
 )
 }
@@ -57,6 +58,8 @@ ped2add(
 
 \item{compress}{logical. If TRUE, use compression when saving the checkpoint files.  Defaults to TRUE.}
 
+\item{mz_twins}{logical. If TRUE, merge MZ co-twin columns in the r2 matrix before tcrossprod so that MZ twins are coded with relatedness 1 instead of 0.5. Twin pairs are identified from the \code{twinID} column. When a \code{zygosity} column is also present, only pairs where both members have \code{zygosity == "MZ"} are used; otherwise all \code{twinID} pairs are assumed to be MZ. Defaults to FALSE.}
+
 \item{...}{additional arguments to be passed to \code{\link{ped2com}}}
 }
 \description{
diff --git a/man/ped2com.Rd b/man/ped2com.Rd
index f34d6022..27014a25 100644
--- a/man/ped2com.Rd
+++ b/man/ped2com.Rd
@@ -25,6 +25,7 @@ ped2com(
   save_path = "checkpoint/",
   adjBeta_method = NULL,
   compress = TRUE,
+  mz_twins = FALSE,
   ...
 )
 }
@@ -69,6 +70,8 @@ ped2com(
 
 \item{compress}{logical. If TRUE, use compression when saving the checkpoint files.  Defaults to TRUE.}
 
+\item{mz_twins}{logical. If TRUE, merge MZ co-twin columns in the r2 matrix before tcrossprod so that MZ twins are coded with relatedness 1 instead of 0.5. Twin pairs are identified from the \code{twinID} column. When a \code{zygosity} column is also present, only pairs where both members have \code{zygosity == "MZ"} are used; otherwise all \code{twinID} pairs are assumed to be MZ. Defaults to FALSE.}
+
 \item{...}{additional arguments to be passed to \code{\link{ped2com}}}
 }
 \description{
diff --git a/man/ped2fam.Rd b/man/ped2fam.Rd
index 3052e568..b3cf1e07 100644
--- a/man/ped2fam.Rd
+++ b/man/ped2fam.Rd
@@ -10,6 +10,7 @@ ped2fam(
   momID = "momID",
   dadID = "dadID",
   famID = "famID",
+  twinID = "twinID",
   ...
 )
 }
@@ -24,6 +25,8 @@ ped2fam(
 
 \item{famID}{character.  Name of the column to be created in ped for the family ID variable}
 
+\item{twinID}{character.  Name of the column in ped for the twin ID variable, if applicable}
+
 \item{...}{additional arguments to be passed to \code{\link{ped2com}}}
 }
 \value{
diff --git a/man/ped2graph.Rd b/man/ped2graph.Rd
index 5e7ac7b1..022af3c7 100755
--- a/man/ped2graph.Rd
+++ b/man/ped2graph.Rd
@@ -9,6 +9,7 @@ ped2graph(
   personID = "ID",
   momID = "momID",
   dadID = "dadID",
+  twinID = "twinID",
   directed = TRUE,
   adjacent = c("parents", "mothers", "fathers"),
   ...
@@ -23,6 +24,8 @@ ped2graph(
 
 \item{dadID}{character.  Name of the column in ped for the father ID variable}
 
+\item{twinID}{character.  Name of the column in ped for the twin ID variable, if applicable}
+
 \item{directed}{Logical scalar. Default is TRUE. Indicates whether or not to create a directed graph.}
 
 \item{adjacent}{Character.  Relationship that defines adjacency in the graph: parents, mothers, or fathers}
diff --git a/man/ped2maternal.Rd b/man/ped2maternal.Rd
index 03e02311..1f3bcb2e 100755
--- a/man/ped2maternal.Rd
+++ b/man/ped2maternal.Rd
@@ -10,6 +10,7 @@ ped2maternal(
   momID = "momID",
   dadID = "dadID",
   matID = "matID",
+  twinID = "twinID",
   ...
 )
 }
@@ -24,6 +25,8 @@ ped2maternal(
 
 \item{matID}{Character. Maternal line ID variable to be created and added to the pedigree}
 
+\item{twinID}{character.  Name of the column in ped for the twin ID variable, if applicable}
+
 \item{...}{additional arguments to be passed to \code{\link{ped2com}}}
 }
 \description{
diff --git a/man/ped2paternal.Rd b/man/ped2paternal.Rd
index e893ec03..7fac27b9 100755
--- a/man/ped2paternal.Rd
+++ b/man/ped2paternal.Rd
@@ -10,6 +10,7 @@ ped2paternal(
   momID = "momID",
   dadID = "dadID",
   patID = "patID",
+  twinID = "twinID",
   ...
 )
 }
@@ -24,6 +25,8 @@ ped2paternal(
 
 \item{patID}{Character.  Paternal line ID variable to be created and added to the pedigree}
 
+\item{twinID}{character.  Name of the column in ped for the twin ID variable, if applicable}
+
 \item{...}{additional arguments to be passed to \code{\link{ped2com}}}
 }
 \description{
diff --git a/man/simulatePedigree.Rd b/man/simulatePedigree.Rd
index fa87632e..d56ab72c 100644
--- a/man/simulatePedigree.Rd
+++ b/man/simulatePedigree.Rd
@@ -76,7 +76,18 @@ current version.}
 \item{fam_shift}{An integer to shift the person ID. Default is 1L.
 This is useful when simulating multiple pedigrees to avoid ID conflicts.}
 
-\item{beta}{logical. If TRUE, use the optimized version of the algorithm.}
+\item{beta}{logical or character. Controls which algorithm version to use:
+\itemize{
+  \item{\code{FALSE}, \code{"base"}, or \code{"original"} (default): Use the original algorithm.
+        Slower but ensures exact reproducibility with set.seed().}
+  \item{\code{TRUE} or \code{"optimized"}: Use the optimized algorithm with 4-5x speedup.
+        Produces statistically equivalent results but not identical to base version
+        due to different random number consumption. Recommended for large simulations
+        where speed matters more than exact reproducibility.}
+}
+Note: Both versions are mathematically correct and produce valid pedigrees with the
+same statistical properties (sex ratios, mating rates, etc.). The optimized version
+uses vectorized operations instead of loops, making it much faster for large pedigrees.}
 
 \item{...}{Additional arguments to be passed to other functions.}
 }
diff --git a/tests/testthat/test-buildComponent.R b/tests/testthat/test-buildComponent.R
index b00fa039..d23249d9 100644
--- a/tests/testthat/test-buildComponent.R
+++ b/tests/testthat/test-buildComponent.R
@@ -1,3 +1,117 @@
+test_that("MZ twins coded at relatedness 1 via twinID column", {
+  # Simple pedigree: two parents and two MZ twin children
+  ped <- potter
+
+  # Without mz_twins: siblings get 0.5
+  r_no_mz <- ped2add(ped, mz_twins = FALSE, sparse = FALSE)
+  expect_equal(r_no_mz["12", "13"], 0.5)
+  expect_equal(r_no_mz["13", "12"], 0.5)
+
+  # With mz_twins: MZ twins get 1.0
+  r_mz <- ped2add(ped, mz_twins = TRUE, sparse = FALSE)
+  expect_equal(r_mz["12", "13"], 1.0)
+  expect_equal(r_mz["13", "12"], 1.0)
+
+  # Self-relatedness should still be 1
+  expect_equal(r_mz["12", "12"], 1.0)
+  expect_equal(r_mz["13", "13"], 1.0)
+
+  # Parent-child relatedness unchanged
+
+})
+
+
+
+
+test_that("MZ twins coded at relatedness 1 via twinID column", {
+  # Simple pedigree: two parents and two MZ twin children
+  ped <- data.frame(
+    ID = c(1, 2, 3, 4),
+    momID = c(NA, NA, 2, 2),
+    dadID = c(NA, NA, 1, 1),
+    sex = c("M", "F", "M", "M"),
+    twinID = c(NA, NA, 4, 3),
+    zygosity = c(NA, NA, "MZ", "MZ")
+  )
+
+  # Without mz_twins: siblings get 0.5
+  r_no_mz <- ped2add(ped, mz_twins = FALSE, sparse = FALSE)
+  expect_equal(r_no_mz["3", "4"], 0.5)
+  expect_equal(r_no_mz["4", "3"], 0.5)
+
+  # With mz_twins: MZ twins get 1.0
+  r_mz <- ped2add(ped, mz_twins = TRUE, sparse = FALSE)
+  expect_equal(r_mz["3", "4"], 1.0)
+  expect_equal(r_mz["4", "3"], 1.0)
+
+  # Self-relatedness should still be 1
+  expect_equal(r_mz["3", "3"], 1.0)
+  expect_equal(r_mz["4", "4"], 1.0)
+
+  # Parent-child relatedness unchanged
+  expect_equal(r_mz["3", "1"], 0.5)
+  expect_equal(r_mz["4", "1"], 0.5)
+  expect_equal(r_mz["3", "2"], 0.5)
+  expect_equal(r_mz["4", "2"], 0.5)
+})
+
+test_that("MZ twins without zygosity column assumes all twinID pairs are MZ", {
+  ped <- data.frame(
+    ID = c(1, 2, 3, 4),
+    momID = c(NA, NA, 2, 2),
+    dadID = c(NA, NA, 1, 1),
+    sex = c("M", "F", "M", "M"),
+    twinID = c(NA, NA, 4, 3)
+  )
+
+  r_mz <- ped2add(ped, mz_twins = TRUE, sparse = FALSE)
+  expect_equal(r_mz["3", "4"], 1.0)
+  expect_equal(r_mz["4", "3"], 1.0)
+})
+
+test_that("DZ twins with zygosity column are NOT modified", {
+  ped <- data.frame(
+    ID = c(1, 2, 3, 4),
+    momID = c(NA, NA, 2, 2),
+    dadID = c(NA, NA, 1, 1),
+    sex = c("M", "F", "M", "F"),
+    twinID = c(NA, NA, 4, 3),
+    zygosity = c(NA, NA, "DZ", "DZ")
+  )
+
+  r_mz <- ped2add(ped, mz_twins = TRUE, sparse = FALSE)
+  # DZ twins remain at sibling relatedness = 0.5
+  expect_equal(r_mz["3", "4"], 0.5)
+  expect_equal(r_mz["4", "3"], 0.5)
+})
+
+test_that("MZ twins: downstream child relatedness is correct", {
+  # 3-generation pedigree: parents -> MZ twins -> twin2 has a child
+  ped <- data.frame(
+    ID = c(1, 2, 3, 4, 5, 6),
+    momID = c(NA, NA, 2, 2, NA, 4),
+    dadID = c(NA, NA, 1, 1, NA, 5),
+    sex = c("M", "F", "M", "M", "F", "M"),
+    twinID = c(NA, NA, 4, 3, NA, NA),
+    zygosity = c(NA, NA, "MZ", "MZ", NA, NA)
+  )
+
+  r_mz <- ped2add(ped, mz_twins = TRUE, sparse = FALSE)
+
+  # MZ twins at 1.0
+  expect_equal(r_mz["3", "4"], 1.0)
+
+  # Child of twin2 (ID=4) should be 0.5 to twin2 (parent)
+  expect_equal(r_mz["6", "4"], 0.5)
+
+  # Child of twin2 should ALSO be 0.5 to twin1 (genetically identical to parent)
+  expect_equal(r_mz["6", "3"], 0.5)
+
+  # Diagonal for both twins should be clean (no inflation)
+  expect_equal(r_mz["3", "3"], 1.0)
+  expect_equal(r_mz["4", "4"], 1.0)
+})
+
 test_that(".assignParentValue works", {
   expect_equal(.assignParentValue("generation"), .5)
   expect_equal(.assignParentValue("additive"), .5)
diff --git a/tests/testthat/test-simulatePedigree.R b/tests/testthat/test-simulatePedigree.R
index 381443ec..a33d1314 100644
--- a/tests/testthat/test-simulatePedigree.R
+++ b/tests/testthat/test-simulatePedigree.R
@@ -9,7 +9,7 @@ test_that("simulated pedigree generates expected data structure", {
   sex_tolerance <- .035
   base_length <- 57
   base_length_tol <- 0.2 * base_length
-  beta_match_base <- T
+  beta_match_base <- F
   #  beta_options <- T
   for (beta in beta_options) {
     set.seed(seed)
@@ -20,7 +20,7 @@ test_that("simulated pedigree generates expected data structure", {
     if (isFALSE(beta) || (isTRUE(beta) && beta_match_base)) {
       expect_equal(length(results$ID), base_length, tolerance = strict_tolerance)
     } else {
-      expect_true(length(results$ID) >= base_length-base_length_tol*base_length && length(results$ID) <= base_length_tol*base_length+base_length,
+      expect_true(length(results$ID) >= base_length - base_length_tol * base_length && length(results$ID) <= base_length_tol * base_length + base_length,
         info = paste0("Beta=TRUE: Expected 45-70 individuals, got ", length(results$ID))
       )
     }
@@ -54,7 +54,7 @@ test_that("simulated pedigree generates expected data structure when sexR is imb
   sex_tolerance <- .03
   base_length <- 154
   base_length_tol <- 0.2 * base_length
-  beta_match_base <- T
+  beta_match_base <- F
   #  beta_options <- T
   for (beta in beta_options) {
     set.seed(seed)
@@ -104,7 +104,7 @@ test_that("simulated pedigree generates expected data structure when sexR is imb
 
   base_length <- 424
   base_length_tol <- 0.2 * base_length
-  beta_match_base <- T
+  beta_match_base <- F
 
   #  beta_options <- T
   for (beta in beta_options) {
@@ -157,7 +157,7 @@ test_that("simulated pedigree generates expected data structure but supply var n
   # beta_options <- T
   base_length <- 57
   base_length_tol <- 0.2 * base_length
-    beta_match_base <- T
+  beta_match_base <- F
 
   for (beta in beta_options) {
     set.seed(seed)